CODE_D% = P% LOAD_D% = LOAD% + P% - CODE%ELITE D FILE.tnpr LDX #12 \ If QQ29 > 12 then jump to kg below, as this cargo CPX QQ29 \ type is gold, platinum, gem-stones or alien items, BCC kg \ and they have different cargo limits to the standard \ tonne canisters CLC \ Clear the C flag for the addition below .Tml \ Here we count the tonne canisters we have in the hold \ and add to A to see if we have enough room for A more \ tonnes of cargo, using X as the loop counter, starting \ with X = 12 ADC QQ20,X \ Set A = A + the number of tonnes we have in the hold \ of market item number X BCS n_over \ If the addition overflowed, jump to n_over to return \ from the subroutine with the C flag set, as the hold \ is already full DEX \ Decrement the loop counter BPL Tml \ Loop back to add in the next market item in the hold, \ until we have added up all market items from 12 \ (minerals) down to 0 (food) CMP new_hold \ If A < new_hold then the C flag will be clear (we have \ room in the hold) \ \ If A >= new_hold then the C flag will be set (we do \ not have room in the hold) .n_over RTS \ Return from the subroutine .kg \ Here we count the number of items of this type that \ we already have in the hold, and add to A to see if \ we have enough room for A more units LDY QQ29 \ Set Y to the item number we want to add ADC QQ20,Y \ Set A = A + the number of units of this item that we \ already have in the hold RTS \ Return from the subroutineName: tnpr [Show more] Type: Subroutine Category: Market Summary: Work out if we have space for a specific amount of cargoContext: See this subroutine on its own page References: This subroutine is called as follows: * TT219 calls tnpr * EQSHP calls via Tml
Given a market item and an amount, work out whether there is room in the cargo hold for this item. For standard tonne canisters, the limit is given by size of the cargo hold of our current ship. For items measured in kg (gold, platinum), g (gem-stones) and alien items, there is no limit.
Arguments: A The number of units of this market item QQ29 The type of market item (see QQ23 for a list of market item numbers)
Returns: C flag Returns the result: * Set if there is no room for this item * Clear if there is room for this item
Other entry points: Tml Calculate the sum of the following, returning the C flag according to whether this all fits into the hold: * The total tonnage of the first X items of cargo * The value in A * Plus one more tonne if the C flag is set on entry This is called with X = 12, A = the number of alien items in the hold, and the C flag set, to see if there is room for one more tonne in the hold.TT20 JSR P%+3 \ This line calls the line below as a subroutine, which \ does two twists before returning here, and then we \ fall through to the line below for another two \ twists, so the net effect of these two consecutive \ JSR calls is four twists, not counting the ones \ inside your head as you try to follow this process JSR P%+3 \ This line calls TT54 as a subroutine to do a twist, \ and then falls through into TT54 to do another twist \ before returning from the subroutineName: TT20 [Show more] Type: Subroutine Category: Universe Summary: Twist the selected system's seeds four times Deep dive: Twisting the system seeds Galaxy and system seedsContext: See this subroutine on its own page References: This subroutine is called as follows: * cour_count calls TT20 * HME2 calls TT20 * TT111 calls TT20 * TT22 calls TT20 * TT23 calls TT20
Twist the three 16-bit seeds in QQ15 (selected system) four times, to generate the next system..TT54 LDA QQ15 \ X = tmp_lo = s0_lo + s1_lo CLC ADC QQ15+2 TAX LDA QQ15+1 \ Y = tmp_hi = s1_hi + s1_hi + C ADC QQ15+3 TAY LDA QQ15+2 \ s0_lo = s1_lo STA QQ15 LDA QQ15+3 \ s0_hi = s1_hi STA QQ15+1 LDA QQ15+5 \ s1_hi = s2_hi STA QQ15+3 LDA QQ15+4 \ s1_lo = s2_lo STA QQ15+2 CLC \ s2_lo = X + s1_lo TXA ADC QQ15+2 STA QQ15+4 TYA \ s2_hi = Y + s1_hi + C ADC QQ15+3 STA QQ15+5 RTS \ The twist is complete so return from the subroutineName: TT54 [Show more] Type: Subroutine Category: Universe Summary: Twist the selected system's seeds Deep dive: Twisting the system seeds Galaxy and system seedsContext: See this subroutine on its own page References: This subroutine is called as follows: * cpl calls TT54
This routine twists the three 16-bit seeds in QQ15 once. If we start with seeds s0, s1 and s2 and we want to work out their new values after we perform a twist (let's call the new values s0´, s1´ and s2´), then: s0´ = s1 s1´ = s2 s2´ = s0 + s1 + s2 So given an existing set of seeds in s0, s1 and s2, we can get the new values s0´, s1´ and s2´ simply by doing the above sums. And if we want to do the above in-place without creating three new s´ variables, then we can do the following: tmp = s0 + s1 s0 = s1 s1 = s2 s2 = tmp + s1 So this is what we do in this routine, where each seed is a 16-bit number..TT146 LDA QQ8 \ Take the two bytes of the 16-bit value in QQ8 and ORA QQ8+1 \ OR them together to check whether there are any BNE TT63 \ non-zero bits, and if so, jump to TT63 to print the \ distance INC YC \ The distance is zero, so we just move the text cursor RTS \ in YC down by one line and return from the subroutine .TT63 LDA #191 \ Print recursive token 31 ("DISTANCE") followed by JSR TT68 \ a colon LDX QQ8 \ Load (Y X) from QQ8, which contains the 16-bit LDY QQ8+1 \ distance we want to show SEC \ Set the C flag so that the call to pr5 will include a \ decimal point, and display the value as (Y X) / 10 JSR pr5 \ Print (Y X) to 5 digits, including a decimal point LDA #195 \ Set A to the recursive token 35 (" LIGHT YEARS") and \ fall through into TT60 to print the token followed \ by a paragraph breakName: TT146 [Show more] Type: Subroutine Category: Universe Summary: Print the distance to the selected system in light yearsContext: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls TT146 * TT25 calls TT146
If it is non-zero, print the distance to the selected system in light years. If it is zero, just move the text cursor down a line. Specifically, if the distance in QQ8 is non-zero, print token 31 ("DISTANCE"), then a colon, then the distance to one decimal place, then token 35 ("LIGHT YEARS"). If the distance is zero, move the cursor down one line..TT60 JSR TT27 \ Print the text token in A and fall through into TTX69 \ to print the paragraph breakName: TT60 [Show more] Type: Subroutine Category: Text Summary: Print a text token and a paragraph breakContext: See this subroutine on its own page References: This subroutine is called as follows: * TT213 calls TT60 * TT25 calls TT60
Print a text token (i.e. a character, control code, two-letter token or recursive token). Then print a paragraph break (a blank line between paragraphs) by moving the cursor down a line, setting Sentence Case, and then printing a newline.
Arguments: A The text token to be printed.TTX69 INC YC \ Move the text cursor down a line \ Fall through into TT69 to set Sentence Case and print \ a newlineName: TTX69 [Show more] Type: Subroutine Category: Text Summary: Print a paragraph breakContext: See this subroutine on its own page References: This subroutine is called as follows: * TT25 calls TTX69
Print a paragraph break (a blank line between paragraphs) by moving the cursor down a line, setting Sentence Case, and then printing a newline..TT69 LDA #%10000000 \ Set bit 7 of QQ17 to switch to Sentence Case STA QQ17 \ Fall through into TT67 to print a newline.TT67 LDA #12 \ Load a newline character into A JMP TT27 \ Print the text token in A and return from the \ subroutine using a tail callName: TT67 [Show more] Type: Subroutine Category: Text Summary: Print a newlineContext: See this subroutine on its own page References: This subroutine is called as follows: * CLYNS calls TT67 * confirm calls TT67 * EQSHP calls TT67 * menu calls TT67 * n_buyship calls TT67 * NWDAV4 calls TT67 * plf calls TT67 * sell_jump calls TT67 * STATUS calls TT67 * TT208 calls TT67 * TT219 calls TT67.TT70 LDA #173 \ Print recursive token 13 ("MAINLY ") JSR TT27 JMP TT72 \ Jump to TT72 to continue printing system data as part \ of routine TT25Name: TT70 [Show more] Type: Subroutine Category: Universe Summary: Display "MAINLY " and jump to TT72Context: See this subroutine on its own page References: This subroutine is called as follows: * TT25 calls TT70
This subroutine is called by TT25 when displaying a system's economy..spc JSR TT27 \ Print the text token in A JMP TT162 \ Print a space and return from the subroutine using a \ tail callName: spc [Show more] Type: Subroutine Category: Text Summary: Print a text token followed by a spaceContext: See this subroutine on its own page References: This subroutine is called as follows: * dn calls spc * EQSHP calls spc * qv calls spc * STATUS calls spc * TT25 calls spc
Print a text token (i.e. a character, control code, two-letter token or recursive token) followed by a space.
Arguments: A The text token to be printed.TT25 JSR CTRL \ Scan the keyboard to see if CTRL is currently pressed, \ returning a negative value in A if it is BPL not_cyclop \ If CTRL is not being pressed, jump to not_cyclop to \ skip the next instruction LDA dockedp \ If dockedp is non-zero, then we are not docked and BNE not_cyclop \ can't show the encyclopedia, so jump to not_cyclop to \ skip the following instruction JMP encyclopedia \ CTRL-f6 is being pressed, so jump to encyclopedia to \ show the Encyclopedia screen .not_cyclop LDA #1 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 1 LDA #9 \ Move the text cursor to column 9 STA XC LDA #163 \ Print recursive token 3 ("DATA ON {selected system JSR NLIN3 \ name}" and draw a horizontal line at pixel row 19 \ to box in the title JSR TTX69 \ Print a paragraph break and set Sentence Case JSR TT146 \ If the distance to this system is non-zero, print \ "DISTANCE", then the distance, "LIGHT YEARS" and a \ paragraph break, otherwise just move the cursor down \ a line LDA #194 \ Print recursive token 34 ("ECONOMY") followed by JSR TT68 \ a colon LDA QQ3 \ The system economy is determined by the value in QQ3, \ so fetch it into A. First we work out the system's \ prosperity as follows: \ \ QQ3 = 0 or 5 = %000 or %101 = Rich \ QQ3 = 1 or 6 = %001 or %110 = Average \ QQ3 = 2 or 7 = %010 or %111 = Poor \ QQ3 = 3 or 4 = %011 or %100 = Mainly CLC \ If (QQ3 + 1) >> 1 = %10, i.e. if QQ3 = %011 or %100 ADC #1 \ (3 or 4), then call TT70, which prints "MAINLY " and LSR A \ jumps down to TT72 to print the type of economy CMP #%00000010 BEQ TT70 LDA QQ3 \ If (QQ3 + 1) >> 1 < %10, i.e. if QQ3 = %000, %001 or BCC TT71 \ %010 (0, 1 or 2), then jump to TT71 with A set to the \ original value of QQ3 SBC #5 \ Here QQ3 = %101, %110 or %111 (5, 6 or 7), so subtract CLC \ 5 to bring it down to 0, 1 or 2 (the C flag is already \ set so the SBC will be correct) .TT71 ADC #170 \ A is now 0, 1 or 2, so print recursive token 10 + A. JSR TT27 \ This means that: \ \ QQ3 = 0 or 5 prints token 10 ("RICH ") \ QQ3 = 1 or 6 prints token 11 ("AVERAGE ") \ QQ3 = 2 or 7 prints token 12 ("POOR ") .TT72 LDA QQ3 \ Now to work out the type of economy, which is LSR A \ determined by bit 2 of QQ3, as follows: LSR A \ \ QQ3 bit 2 = 0 = Industrial \ QQ3 bit 2 = 1 = Agricultural \ \ So we fetch QQ3 into A and set A = bit 2 of QQ3 using \ two right shifts (which will work as QQ3 is only a \ 3-bit number) CLC \ Print recursive token 8 + A, followed by a paragraph ADC #168 \ break and Sentence Case, so: JSR TT60 \ \ QQ3 bit 2 = 0 prints token 8 ("INDUSTRIAL") \ QQ3 bit 2 = 1 prints token 9 ("AGRICULTURAL") LDA #162 \ Print recursive token 2 ("GOVERNMENT") followed by JSR TT68 \ a colon LDA QQ4 \ The system's government is determined by the value in \ QQ4, so fetch it into A CLC \ Print recursive token 17 + A, followed by a paragraph ADC #177 \ break and Sentence Case, so: JSR TT60 \ \ QQ4 = 0 prints token 17 ("ANARCHY") \ QQ4 = 1 prints token 18 ("FEUDAL") \ QQ4 = 2 prints token 19 ("MULTI-GOVERNMENT") \ QQ4 = 3 prints token 20 ("DICTATORSHIP") \ QQ4 = 4 prints token 21 ("COMMUNIST") \ QQ4 = 5 prints token 22 ("CONFEDERACY") \ QQ4 = 6 prints token 23 ("DEMOCRACY") \ QQ4 = 7 prints token 24 ("CORPORATE STATE") LDA #196 \ Print recursive token 36 ("TECH.LEVEL") followed by a JSR TT68 \ colon LDX QQ5 \ Fetch the tech level from QQ5 and increment it, as it INX \ is stored in the range 0-14 but the displayed range \ should be 1-15 CLC \ Call pr2 to print the technology level as a 3-digit JSR pr2 \ number without a decimal point (by clearing the C \ flag) JSR TTX69 \ Print a paragraph break and set Sentence Case LDA #192 \ Print recursive token 32 ("POPULATION") followed by a JSR TT68 \ colon SEC \ Call pr2 to print the population as a 3-digit number LDX QQ6 \ with a decimal point (by setting the C flag), so the JSR pr2 \ number printed will be population / 10 LDA #198 \ Print recursive token 38 (" BILLION"), followed by a JSR TT60 \ paragraph break and Sentence Case LDA #'(' \ Print an opening bracket JSR TT27 LDA QQ15+4 \ Now to calculate the species, so first check bit 7 of BMI TT75 \ s2_lo, and if it is set, jump to TT75 as this is an \ alien species LDA #188 \ Bit 7 of s2_lo is clear, so print recursive token 28 JSR TT27 \ ("HUMAN COLONIAL") JMP TT76 \ Jump to TT76 to print "S)" and a paragraph break, so \ the whole species string is "(HUMAN COLONIALS)" .TT75 LDA QQ15+5 \ This is an alien species, and we start with the first LSR A \ adjective, so fetch bits 2-7 of s2_hi into A and push LSR A \ onto the stack so we can use this later PHA AND #%00000111 \ Set A = bits 0-2 of A (so that's bits 2-4 of s2_hi) CMP #3 \ If A >= 3, jump to TT205 to skip the first adjective, BCS TT205 ADC #227 \ Otherwise A = 0, 1 or 2, so print recursive token JSR spc \ 67 + A, followed by a space, so: \ \ A = 0 prints token 67 ("LARGE") and a space \ A = 1 prints token 68 ("FIERCE") and a space \ A = 2 prints token 69 ("SMALL") and a space .TT205 PLA \ Now for the second adjective, so restore A to bits LSR A \ 2-7 of s2_hi, and throw away bits 2-4 to leave LSR A \ A = bits 5-7 of s2_hi LSR A CMP #6 \ If A >= 6, jump to TT206 to skip the second adjective BCS TT206 ADC #230 \ Otherwise A = 0 to 5, so print recursive token JSR spc \ 70 + A, followed by a space, so: \ \ A = 0 prints token 70 ("GREEN") and a space \ A = 1 prints token 71 ("RED") and a space \ A = 2 prints token 72 ("YELLOW") and a space \ A = 3 prints token 73 ("BLUE") and a space \ A = 4 prints token 74 ("BLACK") and a space \ A = 5 prints token 75 ("HARMLESS") and a space .TT206 LDA QQ15+3 \ Now for the third adjective, so EOR the high bytes of EOR QQ15+1 \ s0 and s1 and extract bits 0-2 of the result: AND #%00000111 \ STA QQ19 \ A = (s0_hi EOR s1_hi) AND %111 \ \ storing the result in QQ19 so we can use it later CMP #6 \ If A >= 6, jump to TT207 to skip the third adjective BCS TT207 ADC #236 \ Otherwise A = 0 to 5, so print recursive token JSR spc \ 76 + A, followed by a space, so: \ \ A = 0 prints token 76 ("SLIMY") and a space \ A = 1 prints token 77 ("BUG-EYED") and a space \ A = 2 prints token 78 ("HORNED") and a space \ A = 3 prints token 79 ("BONY") and a space \ A = 4 prints token 80 ("FAT") and a space \ A = 5 prints token 81 ("FURRY") and a space .TT207 LDA QQ15+5 \ Now for the actual species, so take bits 0-1 of AND #%00000011 \ s2_hi, add this to the value of A that we used for CLC \ the third adjective, and take bits 0-2 of the result ADC QQ19 AND #%00000111 ADC #242 \ A = 0 to 7, so print recursive token 82 + A, so: JSR TT27 \ \ A = 0 prints token 82 ("RODENT") \ A = 1 prints token 83 ("FROG") \ A = 2 prints token 84 ("LIZARD") \ A = 3 prints token 85 ("LOBSTER") \ A = 4 prints token 86 ("BIRD") \ A = 5 prints token 87 ("HUMANOID") \ A = 6 prints token 88 ("FELINE") \ A = 7 prints token 89 ("INSECT") .TT76 LDA #'S' \ Print an "S" to pluralise the species JSR TT27 LDA #')' \ And finally, print a closing bracket, followed by a JSR TT60 \ paragraph break and Sentence Case, to end the species \ section LDA #193 \ Print recursive token 33 ("GROSS PRODUCTIVITY"), JSR TT68 \ followed by a colon LDX QQ7 \ Fetch the 16-bit productivity value from QQ7 into LDY QQ7+1 \ (Y X) JSR pr6 \ Print (Y X) to 5 digits with no decimal point JSR TT162 \ Print a space LDA #0 \ Set QQ17 = 0 to switch to ALL CAPS STA QQ17 LDA #'M' \ Print "M" JSR TT27 LDA #226 \ Print recursive token 66 (" CR"), followed by a JSR TT60 \ paragraph break and Sentence Case LDA #250 \ Print recursive token 90 ("AVERAGE RADIUS"), followed JSR TT68 \ by a colon \ The average radius is calculated like this: \ \ ((s2_hi AND %1111) + 11) * 256 + s1_hi \ \ or, in terms of memory locations: \ \ ((QQ15+5 AND %1111) + 11) * 256 + QQ15+3 \ \ Because the multiplication is by 256, this is the \ same as saying a 16-bit number, with high byte: \ \ (QQ15+5 AND %1111) + 11 \ \ and low byte: \ \ QQ15+3 \ \ so we can set this up in (Y X) and call the pr5 \ routine to print it out LDA QQ15+5 \ Set A = QQ15+5 LDX QQ15+3 \ Set X = QQ15+3 AND #%00001111 \ Set Y = (A AND %1111) + 11 CLC ADC #11 TAY JSR pr5 \ Print (Y X) to 5 digits, not including a decimal \ point, as the C flag will be clear (as the maximum \ radius will always fit into 16 bits) JSR TT162 \ Print a space LDA #'k' \ Print "km" JSR TT26 LDA #'m' JSR TT26 JSR TTX69 \ Print a paragraph break and set Sentence Case \ By this point, ZZ contains the current system number \ which PDESC requires. It gets put there in the TT102 \ routine, which calls TT111 to populate ZZ before \ calling TT25 (this routine) JMP PDESC \ Jump to PDESC to print the system's extended \ description, returning from the subroutine using a \ tail callName: TT25 [Show more] Type: Subroutine Category: Universe Summary: Show the Data on System screen (red key f6) or Encyclopedia screen (CTRL-f6) Deep dive: Generating system data Galaxy and system seedsContext: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls TT25 * TT70 calls via TT72
Other entry points: TT72 Used by TT70 to re-enter the routine after displaying "MAINLY" for the economy type.TT24 LDA QQ15+1 \ Fetch s0_hi and extract bits 0-2 to determine the AND #%00000111 \ system's economy, and store in QQ3 STA QQ3 LDA QQ15+2 \ Fetch s1_lo and extract bits 3-5 to determine the LSR A \ system's government, and store in QQ4 LSR A LSR A AND #%00000111 STA QQ4 LSR A \ If government isn't anarchy or feudal, skip to TT77, BNE TT77 \ as we need to fix the economy of anarchy and feudal \ systems so they can't be rich LDA QQ3 \ Set bit 1 of the economy in QQ3 to fix the economy ORA #%00000010 \ for anarchy and feudal governments STA QQ3 .TT77 LDA QQ3 \ Now to work out the tech level, which we do like this: EOR #%00000111 \ CLC \ flipped_economy + (s1_hi AND %11) + (government / 2) STA QQ5 \ \ or, in terms of memory locations: \ \ QQ5 = (QQ3 EOR %111) + (QQ15+3 AND %11) + (QQ4 / 2) \ \ We start by setting QQ5 = QQ3 EOR %111 LDA QQ15+3 \ We then take the first 2 bits of s1_hi (QQ15+3) and AND #%00000011 \ add it into QQ5 ADC QQ5 STA QQ5 LDA QQ4 \ And finally we add QQ4 / 2 and store the result in LSR A \ QQ5, using LSR then ADC to divide by 2, which rounds ADC QQ5 \ up the result for odd-numbered government types STA QQ5 ASL A \ Now to work out the population, like so: ASL A \ ADC QQ3 \ (tech level * 4) + economy + government + 1 ADC QQ4 \ ADC #1 \ or, in terms of memory locations: STA QQ6 \ \ QQ6 = (QQ5 * 4) + QQ3 + QQ4 + 1 LDA QQ3 \ Finally, we work out productivity, like this: EOR #%00000111 \ ADC #3 \ (flipped_economy + 3) * (government + 4) STA P \ * population LDA QQ4 \ * 8 ADC #4 \ STA Q \ or, in terms of memory locations: JSR MULTU \ \ QQ7 = (QQ3 EOR %111 + 3) * (QQ4 + 4) * QQ6 * 8 \ \ We do the first step by setting P to the first \ expression in brackets and Q to the second, and \ calling MULTU, so now (A P) = P * Q. The highest this \ can be is 10 * 11 (as the maximum values of economy \ and government are 7), so the high byte of the result \ will always be 0, so we actually have: \ \ P = P * Q \ = (flipped_economy + 3) * (government + 4) LDA QQ6 \ We now take the result in P and multiply by the STA Q \ population to get the productivity, by setting Q to JSR MULTU \ the population from QQ6 and calling MULTU again, so \ now we have: \ \ (A P) = P * population ASL P \ Next we multiply the result by 8, as a 16-bit number, ROL A \ so we shift both bytes to the left three times, using ASL P \ the C flag to carry bits from bit 7 of the low byte ROL A \ into bit 0 of the high byte ASL P ROL A STA QQ7+1 \ Finally, we store the productivity in two bytes, with LDA P \ the low byte in QQ7 and the high byte in QQ7+1 STA QQ7 RTS \ Return from the subroutineName: TT24 [Show more] Type: Subroutine Category: Universe Summary: Calculate system data from the system seeds Deep dive: Generating system data Galaxy and system seedsContext: See this subroutine on its own page References: This subroutine is called as follows: * TT111 calls TT24
Calculate system data from the seeds in QQ15 and store them in the relevant locations. Specifically, this routine calculates the following from the three 16-bit seeds in QQ15 (using only s0_hi, s1_hi and s1_lo): QQ3 = economy (0-7) QQ4 = government (0-7) QQ5 = technology level (0-14) QQ6 = population * 10 (1-71) QQ7 = productivity (96-62480) The ranges of the various values are shown in brackets. Note that the radius and type of inhabitant are calculated on-the-fly in the TT25 routine when the system data gets displayed, so they aren't calculated here..TT22 LDA #64 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 32 (Long- \ range Chart) LDA #7 \ Move the text cursor to column 7 STA XC JSR TT81 \ Set the seeds in QQ15 to those of system 0 in the \ current galaxy (i.e. copy the seeds from QQ21 to QQ15) LDA #199 \ Print recursive token 39 ("GALACTIC CHART{galaxy JSR TT27 \ number right-aligned to width 3}") JSR NLIN \ Draw a horizontal line at pixel row 23 to box in the \ title and act as the top frame of the chart, and move \ the text cursor down one line LDA #152 \ Draw a screen-wide horizontal line at pixel row 152 JSR NLIN2 \ for the bottom edge of the chart, so the chart itself \ is 128 pixels high, starting on row 24 and ending on \ row 151 JSR TT14 \ Call TT14 to draw a circle with crosshairs at the \ current system's galactic coordinates LDX #0 \ We're now going to plot each of the galaxy's systems, \ so set up a counter in X for each system, starting at \ 0 and looping through to 255 .TT83 STX XSAV \ Store the counter in XSAV LDX QQ15+3 \ Fetch the s1_hi seed into X, which gives us the \ galactic x-coordinate of this system LDY QQ15+4 \ Fetch the s2_lo seed and set bits 4 and 6, storing the TYA \ result in ZZ to give a random number between 80 and ORA #%01010000 \ (but which will always be the same for this system). STA ZZ \ We use this value to determine the size of the point \ for this system on the chart by passing it as the \ distance argument to the PIXEL routine below LDA QQ15+1 \ Fetch the s0_hi seed into A, which gives us the \ galactic y-coordinate of this system LSR A \ We halve the y-coordinate because the galaxy in \ in Elite is rectangular rather than square, and is \ twice as wide (x-axis) as it is high (y-axis), so the \ chart is 256 pixels wide and 128 high CLC \ Add 24 to the halved y-coordinate and store in XX15+1 ADC #24 \ (as the top of the chart is on pixel row 24, just STA XX15+1 \ below the line we drew on row 23 above) JSR PIXEL \ Call PIXEL to draw a point at (X, A), with the size of \ the point dependent on the distance specified in ZZ \ (so a high value of ZZ will produce a 1-pixel point, \ a medium value will produce a 2-pixel dash, and a \ small value will produce a 4-pixel square) JSR TT20 \ We want to move on to the next system, so call TT20 \ to twist the three 16-bit seeds in QQ15 LDX XSAV \ Restore the loop counter from XSAV INX \ Increment the counter BNE TT83 \ If X > 0 then we haven't done all 256 systems yet, so \ loop back up to TT83 LDA QQ9 \ Set QQ19 to the selected system's x-coordinate STA QQ19 LDA QQ10 \ Set QQ19+1 to the selected system's y-coordinate, LSR A \ halved to fit it into the chart STA QQ19+1 LDA #4 \ Set QQ19+2 to size 4 for the crosshairs size STA QQ19+2 \ Fall through into TT15 to draw crosshairs of size 4 at \ the selected system's coordinates.TT15 LDA #24 \ Set A to 24, which we will use as the minimum \ screen indent for the crosshairs (i.e. the minimum \ distance from the top-left corner of the screen) LDX QQ11 \ If the current view is not the Short-range Chart, BPL P%+4 \ which is the only view with bit 7 set, then skip the \ following instruction LDA #0 \ This is the Short-range Chart, so set A to 0, so the \ crosshairs can go right up against the screen edges STA QQ19+5 \ Set QQ19+5 to A, which now contains the correct indent \ for this view LDA QQ19 \ Set A = crosshairs x-coordinate - crosshairs size SEC \ to get the x-coordinate of the left edge of the SBC QQ19+2 \ crosshairs BCS TT84 \ If the above subtraction didn't underflow, then A is \ positive, so skip the next instruction LDA #0 \ The subtraction underflowed, so set A to 0 so the \ crosshairs don't spill out of the left of the screen .TT84 \ In the following, the authors have used XX15 for \ temporary storage. XX15 shares location with X1, Y1, \ X2 and Y2, so in the following, you can consider \ the variables like this: \ \ XX15 is the same as X1 \ XX15+1 is the same as Y1 \ XX15+2 is the same as X2 \ XX15+3 is the same as Y2 \ \ Presumably this routine was written at a different \ time to the line-drawing routine, before the two \ workspaces were merged to save space STA XX15 \ Set XX15 (X1) = A (the x-coordinate of the left edge \ of the crosshairs) LDA QQ19 \ Set A = crosshairs x-coordinate + crosshairs size CLC \ to get the x-coordinate of the right edge of the ADC QQ19+2 \ crosshairs BCC P%+4 \ If the above addition didn't overflow, then A is \ correct, so skip the next instruction LDA #255 \ The addition overflowed, so set A to 255 so the \ crosshairs don't spill out of the right of the screen \ (as 255 is the x-coordinate of the rightmost pixel \ on-screen) STA XX15+2 \ Set XX15+2 (X2) = A (the x-coordinate of the right \ edge of the crosshairs) LDA QQ19+1 \ Set XX15+1 (Y1) = crosshairs y-coordinate + indent CLC \ to get the y-coordinate of the centre of the ADC QQ19+5 \ crosshairs STA XX15+1 JSR HLOIN \ Draw a horizontal line from (X1, Y1) to (X2, Y1), \ which will draw from the left edge of the crosshairs \ to the right edge, through the centre of the \ crosshairs LDA QQ19+1 \ Set A = crosshairs y-coordinate - crosshairs size SEC \ to get the y-coordinate of the top edge of the SBC QQ19+2 \ crosshairs BCS TT86 \ If the above subtraction didn't underflow, then A is \ correct, so skip the next instruction LDA #0 \ The subtraction underflowed, so set A to 0 so the \ crosshairs don't spill out of the top of the screen .TT86 CLC \ Set XX15+1 (Y1) = A + indent to get the y-coordinate ADC QQ19+5 \ of the top edge of the indented crosshairs STA XX15+1 LDA QQ19+1 \ Set A = crosshairs y-coordinate + crosshairs size CLC \ + indent to get the y-coordinate of the bottom edge ADC QQ19+2 \ of the indented crosshairs ADC QQ19+5 CMP #152 \ If A < 152 then skip the following, as the crosshairs BCC TT87 \ won't spill out of the bottom of the screen LDX QQ11 \ A >= 152, so we need to check whether this will fit in \ this view, so fetch the view type BMI TT87 \ If this is the Short-range Chart then the y-coordinate \ is fine, so skip to TT87 LDA #151 \ Otherwise this is the Long-range Chart, so we need to \ clip the crosshairs at a maximum y-coordinate of 151 .TT87 STA XX15+3 \ Set XX15+3 (Y2) = A (the y-coordinate of the bottom \ edge of the crosshairs) LDA QQ19 \ Set XX15 (X1) = the x-coordinate of the centre of the STA XX15 \ crosshairs STA XX15+2 \ Set XX15+2 (X2) = the x-coordinate of the centre of \ the crosshairs JMP LL30 \ Draw a vertical line (X1, Y1) to (X2, Y2), which will \ draw from the top edge of the crosshairs to the bottom \ edge, through the centre of the crosshairs, returning \ from the subroutine using a tail callName: TT15 [Show more] Type: Subroutine Category: Drawing lines Summary: Draw a set of crosshairsContext: See this subroutine on its own page References: This subroutine is called as follows: * SIGHT calls TT15 * TT103 calls TT15 * TT105 calls TT15 * TT14 calls TT15
For all views except the Short-range Chart, the centre is drawn 24 pixels to the right of the y-coordinate given.
Arguments: QQ19 The pixel x-coordinate of the centre of the crosshairs QQ19+1 The pixel y-coordinate of the centre of the crosshairs QQ19+2 The size of the crosshairs.TT126 LDA #104 \ Set QQ19 = 104, for the x-coordinate of the centre of STA QQ19 \ the fixed circle on the Short-range Chart LDA #90 \ Set QQ19+1 = 90, for the y-coordinate of the centre of STA QQ19+1 \ the fixed circle on the Short-range Chart LDA #16 \ Set QQ19+2 = 16, the size of the crosshairs on the STA QQ19+2 \ Short-range Chart JSR TT15 \ Draw the set of crosshairs defined in QQ19, at the \ exact coordinates as this is the Short-range Chart LDA QQ14 \ Set K to the fuel level from QQ14, so this can act as STA K \ the circle's radius (70 being a full tank) JMP TT128 \ Jump to TT128 to draw a circle with the centre at the \ same coordinates as the crosshairs, (QQ19, QQ19+1), \ and radius K that reflects the current fuel levels, \ returning from the subroutine using a tail call .TT14 LDA QQ11 \ If the current view is the Short-range Chart, which BMI TT126 \ is the only view with bit 7 set, then jump up to TT126 \ to draw the crosshairs and circle for that view \ Otherwise this is the Long-range Chart, so we draw the \ crosshairs and circle for that view instead LDA QQ14 \ Set K to the fuel level from QQ14 divided by 4, so LSR A \ this can act as the circle's radius (70 being a full LSR A \ tank, which divides down to a radius of 17) STA K LDA QQ0 \ Set QQ19 to the x-coordinate of the current system, STA QQ19 \ which will be the centre of the circle and crosshairs \ we draw LDA QQ1 \ Set QQ19+1 to the y-coordinate of the current system, LSR A \ halved because the galactic chart is half as high as STA QQ19+1 \ it is wide, which will again be the centre of the \ circle and crosshairs we draw LDA #7 \ Set QQ19+2 = 7, the size of the crosshairs on the STA QQ19+2 \ Long-range Chart JSR TT15 \ Draw the set of crosshairs defined in QQ19, which will \ be drawn 24 pixels to the right of QQ19+1 LDA QQ19+1 \ Add 24 to the y-coordinate of the crosshairs in QQ19+1 CLC \ so that the centre of the circle matches the centre ADC #24 \ of the crosshairs STA QQ19+1 \ Fall through into TT128 to draw a circle with the \ centre at the same coordinates as the crosshairs, \ (QQ19, QQ19+1), and radius K that reflects the \ current fuel levelsName: TT14 [Show more] Type: Subroutine Category: Drawing circles Summary: Draw a circle with crosshairs on a chartContext: See this subroutine on its own page References: This subroutine is called as follows: * TT22 calls TT14 * TT23 calls TT14
Draw a circle with crosshairs at the current system's galactic coordinates..TT128 LDA QQ19 \ Set K3 = the x-coordinate of the centre STA K3 LDA QQ19+1 \ Set K4 = the y-coordinate of the centre STA K4 LDX #0 \ Set the high bytes of K3(1 0) and K4(1 0) to 0 STX K4+1 STX K3+1 INX \ Set LSP = 1 to reset the ball line heap STX LSP INX \ Set STP = 2, the step size for the circle STX STP JMP CIRCLE2 \ Jump to CIRCLE2 to draw a circle with the centre at \ (K3(1 0), K4(1 0)) and radius K, returning from the \ subroutine using a tail callName: TT128 [Show more] Type: Subroutine Category: Drawing circles Summary: Draw a circle on a chart Deep dive: Drawing circlesContext: See this subroutine on its own page References: This subroutine is called as follows: * TT14 calls TT128
Draw a circle with the centre at (QQ19, QQ19+1) and radius K.
Arguments: QQ19 The x-coordinate of the centre of the circle QQ19+1 The y-coordinate of the centre of the circle K The radius of the circle.TT219 LDA #2 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 2 JSR CTRL \ Scan the keyboard to see if CTRL is currently pressed, \ returning a negative value in A if it is BPL buy_ctrl \ If CTRL is not being pressed, jump to buy_ctrl to skip \ the next instruction JMP cour_buy \ CTRL-f1 is being pressed, so jump to cour_buy to show \ the Special Cargo screen, returning from the \ subroutine using a tail call .buy_ctrl JSR TT163 \ Print the column headers for the prices table LDA #%10000000 \ Set bit 7 of QQ17 to switch to Sentence Case, with the STA QQ17 \ next letter in capitals JSR FLKB \ Flush the keyboard buffer LDA #0 \ We're going to loop through all the available market STA QQ29 \ items, so we set up a counter in QQ29 to denote the \ current item and start it at 0 .TT220 JSR TT151 \ Call TT151 to print the item name, market price and \ availability of the current item, and set QQ24 to the \ item's price / 4, QQ25 to the quantity available and \ QQ19+1 to byte #1 from the market prices table for \ this item LDA QQ25 \ If there are some of the current item available, jump BNE TT224 \ to TT224 below to see if we want to buy any JMP TT222 \ Otherwise there are none available, so jump down to \ TT222 to skip this item .TQ4 LDY #176 \ Set Y to the recursive token 16 ("QUANTITY") .Tc JSR TT162 \ Print a space TYA \ Print the recursive token in Y followed by a question JSR prq \ mark .TTX224 JSR dn2 \ Call dn2 to make a short, high beep and delay for 1 \ second .TT224 JSR CLYNS \ Clear the bottom three text rows of the upper screen, \ and move the text cursor to the first cleared row LDA #204 \ Print recursive token 44 ("QUANTITY OF ") JSR TT27 LDA QQ29 \ Print recursive token 48 + QQ29, which will be in the CLC \ range 48 ("FOOD") to 64 ("ALIEN ITEMS"), so this ADC #208 \ prints the current item's name JSR TT27 LDA #'/' \ Print "/" JSR TT27 JSR TT152 \ Print the unit ("t", "kg" or "g") for the current item \ (as the call to TT151 above set QQ19+1 with the \ appropriate value) LDA #'?' \ Print "?" JSR TT27 JSR TT67 \ Print a newline JSR gnum \ Call gnum to get a number from the keyboard, which \ will be the quantity of this item we want to purchase, \ returning the number entered in A and R BCS TQ4 \ If gnum set the C flag, the number entered is greater \ than the quantity available, so jump up to TQ4 to \ display a "Quantity?" error, beep, clear the number \ and try again STA P \ Otherwise we have a valid purchase quantity entered, \ so store the amount we want to purchase in P JSR tnpr \ Call tnpr to work out whether there is room in the \ cargo hold for this item LDY #206 \ Set Y to recursive token 46 (" CARGO{sentence case}") \ to pass to the Tc routine if we call it BCS Tc \ If the C flag is set, then there is no room in the \ cargo hold, jump up to Tc to print a "Cargo?" error, \ beep, clear the number and try again LDA QQ24 \ There is room in the cargo hold, so now to check STA Q \ whether we have enough cash, so fetch the item's \ price / 4, which was returned in QQ24 by the call \ to TT151 above and store it in Q JSR GCASH \ Call GCASH to calculate: \ \ (Y X) = P * Q * 4 \ \ which will be the total price of this transaction \ (as P contains the purchase quantity and Q contains \ the item's price / 4) JSR LCASH \ Subtract (Y X) cash from the cash pot in CASH LDY #197 \ If the C flag is clear, we didn't have enough cash, BCC Tc \ so set Y to the recursive token 37 ("CASH") and jump \ up to Tc to print a "Cash?" error, beep, clear the \ number and try again LDY QQ29 \ Fetch the current market item number from QQ29 into Y LDA R \ Set A to the number of items we just purchased (this \ was set by gnum above) PHA \ Store the quantity just purchased on the stack CLC \ Add the number purchased to the Y-th byte of QQ20, ADC QQ20,Y \ which contains the number of items of this type in STA QQ20,Y \ our hold (so this transfers the bought items into our \ cargo hold) LDA AVL,Y \ Subtract the number of items from the Y-th byte of SEC \ AVL, which contains the number of items of this type SBC R \ that are available on the market STA AVL,Y PLA \ Restore the quantity just purchased BEQ TT222 \ If we didn't buy anything, jump to TT222 to skip the \ following instruction JSR dn \ Call dn to print the amount of cash left in the cash \ pot, then make a short, high beep to confirm the \ purchase, and delay for 1 second .TT222 LDA QQ29 \ Move the text cursor to row QQ29 + 5 (where QQ29 is CLC \ the item number, starting from 0) ADC #5 STA YC LDA #0 \ Move the text cursor to column 0 STA XC INC QQ29 \ Increment QQ29 to point to the next item LDA QQ29 \ If QQ29 >= 17 then jump to BAY2 as we have done the CMP #17 \ last item BCS BAY2 JMP TT220 \ Otherwise loop back to TT220 to print the next market \ item .BAY2 LDA #f9 \ Jump into the main loop at FRCE, setting the key JMP FRCE \ "pressed" to red key f9 (so we show the Inventory \ screen)Name: TT219 [Show more] Type: Subroutine Category: Market Summary: Show the Buy Cargo screen (red key f1) or Special Cargo screen (CTRL-f1)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls TT219 * gnum calls via BAY2 * TT210 calls via BAY2
Other entry points: BAY2 Jump into the main loop at FRCE, setting the key "pressed" to red key f9 (so we show the Inventory screen).sell_yn LDA #205 \ Print recursive token 45 ("SELL") JSR TT27 LDA #206 \ Print extended token 206 ("{all caps}(Y/N)?") JSR DETOK \ Fall through into gnum to get a number from the \ keyboardName: sell_yn [Show more] Type: Subroutine Category: Text Summary: Print a "Sell(Y/N)?" prompt and get a number from the keyboardContext: See this subroutine on its own page References: This subroutine is called as follows: * status_equip calls sell_yn * TT210 calls sell_yn
The arguments and results for this routine are the same as for gnum.
Arguments: QQ25 The maximum number allowed
Returns: A The number entered R Also contains the number entered C flag Set if the number is too large (> QQ25), clear otherwise.gnum LDX #0 \ We will build the number entered in R, so initialise STX R \ it with 0 LDX #12 \ We will check for up to 12 key presses, so set a STX T1 \ counter in T1 .TT223 JSR TT217 \ Scan the keyboard until a key is pressed, and return \ the key's ASCII code in A (and X) LDX R \ If R is non-zero then skip to NWDAV2, as we are BNE NWDAV2 \ already building a number CMP #'y' \ If "Y" was pressed, jump to NWDAV1 to return the BEQ NWDAV1 \ maximum number allowed (i.e. buy/sell the whole stock) CMP #'n' \ If "N" was pressed, jump to NWDAV3 to return from the BEQ NWDAV3 \ subroutine with a result of 0 (i.e. abort transaction) .NWDAV2 STA Q \ Store the key pressed in Q SEC \ Subtract ASCII "0" from the key pressed, to leave the SBC #'0' \ numeric value of the key in A (if it was a number key) BCC OUT \ If A < 0, jump to OUT to load the current number and \ return from the subroutine, as the key pressed was \ RETURN (or some other character with a value less than \ ASCII "0") CMP #10 \ If A >= 10, jump to BAY2 to display the Inventory BCS BAY2 \ screen, as the key pressed was a letter or other \ non-digit and is greater than ASCII "9" STA S \ Store the numeric value of the key pressed in S LDA R \ Fetch the result so far into A CMP #26 \ If A >= 26, where A is the number entered so far, then BCS OUT \ adding a further digit will make it bigger than 256, \ so jump to OUT to return from the subroutine with the \ result in R (i.e. ignore the last key press) ASL A \ Set A = (A * 2) + (A * 8) = A * 10 STA T ASL A ASL A ADC T ADC S \ Add the pressed digit to A and store in R, so R now STA R \ contains its previous value with the new key press \ tacked onto the end CMP QQ25 \ If the result in R = the maximum allowed in QQ25, jump BEQ TT226 \ to TT226 to print the key press and keep looping (the \ BEQ is needed because the BCS below would jump to OUT \ if R >= QQ25, which we don't want) BCS OUT \ If the result in R > QQ25, jump to OUT to return from \ the subroutine with the result in R .TT226 LDA Q \ Print the character in Q (i.e. the key that was JSR TT26 \ pressed, as we stored the ASCII value in Q earlier) DEC T1 \ Decrement the loop counter BNE TT223 \ Loop back to TT223 until we have checked for 12 digits .OUT LDA R \ Set A to the result we have been building in R RTS \ Return from the subroutine .NWDAV1 \ If we get here then "Y" was pressed, so we return the \ maximum number allowed, which is in QQ25 JSR TT26 \ Print the character for the key that was pressed LDA QQ25 \ Set R = QQ25, so we return the maximum value allowed STA R RTS \ Return from the subroutine .NWDAV3 \ If we get here then "N" was pressed, so we return 0 JSR TT26 \ Print the character for the key that was pressed LDA #0 \ Set R = 0, so we return 0 STA R RTS \ Return from the subroutineName: gnum [Show more] Type: Subroutine Category: Market Summary: Get a number from the keyboardContext: See this subroutine on its own page References: This subroutine is called as follows: * cour_buy calls gnum * EQSHP calls gnum * menu calls gnum * n_buyship calls gnum * TT219 calls gnum
Get a number from the keyboard, up to the maximum number in QQ25, for the buying and selling of cargo and equipment. Pressing "Y" will return the maximum number (i.e. buy/sell all items), while pressing "N" will abort the sale and return a 0. Pressing a key with an ASCII code less than ASCII "0" will return a 0 in A (so that includes pressing Space or Return), while pressing a key with an ASCII code greater than ASCII "9" will jump to the Inventory screen (so that includes all letters and most punctuation).
Arguments: QQ25 The maximum number allowed
Returns: A The number entered R Also contains the number entered C flag Set if the number is too large (> QQ25), clear otherwise.sell_jump INC XC \ Move the text cursor down one line LDA #207 \ Print recursive token 47 ("EQUIP") and draw a JSR NLIN3 \ horizontal line at pixel row 19 to box in the title JSR TT69 \ Call TT69 to set Sentence Case and print a newline JSR TT67 \ Print a newline JSR sell_equip \ Call sell_equip to show the Sell Equipment screen, \ which will run through all the equipment apart from \ the escape pod LDA ESCP \ If we do not have an escape pod fitted, in which case BEQ sell_escape \ ESCP will be 0, jump to sell_escape LDA #112 \ We do have an E.C.M. fitted, so print recursive token LDX #30 \ 112 ("ESCAPE POD"), and as this is the Sell Equipment JSR status_equip \ screen, show and process a sell prompt for the piece \ of equipment at LASER+X = LASER+30 = ESCP before \ printing a newline .sell_escape JMP BAY \ Go to the docking bay (i.e. show the Status Mode \ screen) and return from the subroutine with a tail \ callName: sell_jump [Show more] Type: Subroutine Category: Equipment Summary: Show the Sell Equipment screen (CTRL-f2)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT208 calls sell_jump.NWDAV4 JSR TT67 \ Print a newline LDA #176 \ Print recursive token 127 ("ITEM") followed by a JSR prq \ question mark JSR dn2 \ Call dn2 to make a short, high beep and delay for 1 \ second LDY QQ29 \ Fetch the item number we are selling from QQ29 JMP NWDAVxx \ Jump back into the TT210 routine that called NWDAV4Name: NWDAV4 [Show more] Type: Subroutine Category: Market Summary: Print an "ITEM?" error, make a beep and rejoin the TT210 routineContext: See this subroutine on its own page References: This subroutine is called as follows: * TT210 calls NWDAV4.TT208 LDA #4 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 4 (Sell \ Cargo screen) LDA #10 \ Move the text cursor to column 10 STA XC JSR FLKB \ Flush the keyboard buffer LDA #205 \ Print recursive token 45 ("SELL") JSR TT27 JSR CTRL \ Scan the keyboard to see if CTRL is currently pressed, \ returning a negative value in A if it is BMI sell_jump \ If CTRL is being pressed, jump to sell_jump to show \ the Sell Equipment screen (CTRL-f2) LDA #206 \ Print recursive token 46 (" CARGO{sentence case}") JSR NLIN3 \ draw a horizontal line at pixel row 19 to box in the \ title JSR TT67 \ Print a newline \ Fall through into TT210 to show the Inventory screen \ with the option to sellName: TT208 [Show more] Type: Subroutine Category: Market Summary: Show the Sell Cargo screen (red key f2) or Sell Equipment screen (CTRL-f2)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls TT208.TT210 LDY #0 \ We're going to loop through all the available market \ items and check whether we have any in the hold (and, \ if we are in the Sell Cargo screen, whether we want \ to sell any items), so we set up a counter in Y to \ denote the current item and start it at 0 .TT211 STY QQ29 \ Store the current item number in QQ29 .NWDAVxx LDX QQ20,Y \ Fetch into X the amount of the current item that we BEQ TT212 \ have in our cargo hold, which is stored in QQ20+Y, \ and if there are no items of this type in the hold, \ jump down to TT212 to skip to the next item TYA \ Set Y = Y * 4, so this will act as an index into the ASL A \ market prices table at QQ23 for this item (as there ASL A \ are four bytes per item in the table) TAY LDA QQ23+1,Y \ Fetch byte #1 from the market prices table for the STA QQ19+1 \ current item and store it in QQ19+1, for use by the \ call to TT152 below TXA \ Store the amount of item in the hold (in X) on the PHA \ stack JSR TT69 \ Call TT69 to set Sentence Case and print a newline CLC \ Print recursive token 48 + QQ29, which will be in the LDA QQ29 \ range 48 ("FOOD") to 64 ("ALIEN ITEMS"), so this ADC #208 \ prints the current item's name JSR TT27 LDA #14 \ Move the text cursor to column 14, for the item's STA XC \ quantity PLA \ Restore the amount of item in the hold into X TAX STA QQ25 \ Store the amount of this item in the hold in QQ25 CLC \ Print the 8-bit number in X to 3 digits, without a JSR pr2 \ decimal point JSR TT152 \ Print the unit ("t", "kg" or "g") for the market item \ whose byte #1 from the market prices table is in \ QQ19+1 (which we set up above) LDA QQ11 \ If the current view type in QQ11 is not 4 (Sell Cargo CMP #4 \ screen), jump to TT212 to skip the option to sell BNE TT212 \ items JSR sell_yn \ Call sell_yn to print a "Sell(Y/N)?" prompt and get a \ number from the keyboard, which will be the number of \ the item we want to sell, returning the number entered \ in A and R, and setting the C flag if the number is \ bigger than the available amount of this item in QQ25 BEQ TT212 \ If no number was entered, jump to TT212 to move on to \ the next item BCS NWDAV4 \ If the number entered was too big, jump to NWDAV4 to \ print an "ITEM?" error, make a beep and rejoin the \ routine at NWDAVxx above LDA QQ29 \ We are selling this item, so fetch the item number \ from QQ29 LDX #255 \ Set QQ17 = 255 to disable printing STX QQ17 JSR TT151 \ Call TT151 to set QQ24 to the item's price / 4 (the \ routine doesn't print the item details, as we just \ disabled printing) LDY QQ29 \ Subtract R (the number of items we just asked to buy) LDA QQ20,Y \ from the available amount of this item in QQ20, as we SEC \ just bought them SBC R STA QQ20,Y LDA R \ Set P to the amount of this item we just bought STA P LDA QQ24 \ Set Q to the item's price / 4 STA Q JSR MULTU \ Call MULTU to calculate (A P) = P * Q JSR price_xy \ Call price_xy to set (Y X) = (A P) = P * Q JSR MCASH \ Add 4 * (Y X) cash to the cash pot in CASH, i.e. JSR MCASH \ JSR MCASH \ (Y X) = P * Q * 4 JSR MCASH \ \ which will be the total price we make from this sale \ (as P contains the quantity we're selling and Q \ contains the item's price / 4) LDA #0 \ We've made the sale, so set the amount STA QQ17 \ Set QQ17 = 0, which enables printing again .TT212 LDY QQ29 \ Fetch the item number from QQ29 into Y, and increment INY \ Y to point to the next item CPY #17 \ Loop back to TT211 to print the next item in the hold BCC TT211 \ until Y = 17 (at which point we have done the last \ item) LDA QQ11 \ If the current view type in QQ11 is not 4 (Sell Cargo CMP #4 \ screen), skip the next two instructions and just BNE P%+8 \ return from the subroutine JSR dn2 \ This is the Sell Cargo screen, so call dn2 to make a \ short, high beep and delay for 1 second JMP BAY2 \ And then jump to BAY2 to display the Inventory \ screen, as we have finished selling cargo RTS \ Return from the subroutineName: TT210 [Show more] Type: Subroutine Category: Market Summary: Show a list of current cargo in our hold, optionally to sellContext: See this subroutine on its own page References: This subroutine is called as follows: * TT213 calls TT210 * NWDAV4 calls via NWDAVxx
Show a list of current cargo in our hold, either with the ability to sell (the Sell Cargo screen) or without (the Inventory screen), depending on the current view.
Arguments: QQ11 The current view: * 4 = Sell Cargo * 8 = Inventory
Other entry points: NWDAVxx Used to rejoin this routine from the call to NWDAV4.TT213 LDA #8 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 8 (Inventory \ screen) LDA #11 \ Move the text cursor to column 11 to print the screen STA XC \ title LDA #164 \ Print recursive token 4 ("INVENTORY{crlf}") followed JSR TT60 \ by a paragraph break and Sentence Case JSR NLIN4 \ Draw a horizontal line at pixel row 19 to box in the \ title. The authors could have used a call to NLIN3 \ instead and saved the above call to TT60, but you \ just can't optimise everything JSR fwl \ Call fwl to print the fuel and cash levels on two \ separate lines LDA #14 \ Print recursive token 128 ("SPACE") followed by a JSR TT68 \ colon LDX new_hold \ Set X to the amount of free space in our current DEX \ ship's hold, minus 1 as new_hold contains the amount \ of free space plus 1 CLC \ Call pr2 to print the amount of free space as a JSR pr2 \ 3-digit number without a decimal point (by clearing \ the C flag) JSR TT160 \ Print "t" (for tonne) and a space JMP TT210 \ Jump to TT210 to print the contents of our cargo bay \ and return from the subroutine using a tail callName: TT213 [Show more] Type: Subroutine Category: Market Summary: Show the Inventory screen (red key f9)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls TT213.TT16 TXA \ Push the change in X onto the stack (let's call this PHA \ the x-delta) DEY \ Negate the change in Y and push it onto the stack TYA \ (let's call this the y-delta) EOR #&FF PHA JSR TT103 \ Draw small crosshairs at coordinates (QQ9, QQ10), \ which will erase the crosshairs currently there PLA \ Store the y-delta in QQ19+3 and fetch the current STA QQ19+3 \ y-coordinate of the crosshairs from QQ10 into A, ready LDA QQ10 \ for the call to TT123 JSR TT123 \ Call TT123 to move the selected system's galactic \ y-coordinate by the y-delta, putting the new value in \ QQ19+4 LDA QQ19+4 \ Store the updated y-coordinate in QQ10 (the current STA QQ10 \ y-coordinate of the crosshairs) STA QQ19+1 \ This instruction has no effect, as QQ19+1 is \ overwritten below, both in TT103 and TT105 PLA \ Store the x-delta in QQ19+3 and fetch the current STA QQ19+3 \ x-coordinate of the crosshairs from QQ10 into A, ready LDA QQ9 \ for the call to TT123 JSR TT123 \ Call TT123 to move the selected system's galactic \ x-coordinate by the x-delta, putting the new value in \ QQ19+4 LDA QQ19+4 \ Store the updated x-coordinate in QQ9 (the current STA QQ9 \ x-coordinate of the crosshairs) STA QQ19 \ This instruction has no effect, as QQ19 is overwritten \ below, both in TT103 and TT105 \ Now we've updated the coordinates of the crosshairs, \ fall through into TT103 to redraw them at their new \ locationName: TT16 [Show more] Type: Subroutine Category: Charts Summary: Move the crosshairs on a chartContext: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls TT16
Move the chart crosshairs by the amount in X and Y.
Arguments: X The amount to move the crosshairs in the x-axis Y The amount to move the crosshairs in the y-axis.TT103 LDA QQ11 \ Fetch the current view type into A BMI TT105 \ If this is the Short-range Chart screen, jump to TT105 LDA QQ9 \ Store the crosshairs x-coordinate in QQ19 STA QQ19 LDA QQ10 \ Halve the crosshairs y-coordinate and store it in QQ19 LSR A \ (we halve it because the Long-range Chart is half as STA QQ19+1 \ high as it is wide) LDA #4 \ Set QQ19+2 to 4 denote crosshairs of size 4 STA QQ19+2 JMP TT15 \ Jump to TT15 to draw crosshairs of size 4 at the \ crosshairs coordinates, returning from the subroutine \ using a tail callName: TT103 [Show more] Type: Subroutine Category: Charts Summary: Draw a small set of crosshairs on a chartContext: See this subroutine on its own page References: This subroutine is called as follows: * hm calls TT103 * HME2 calls TT103 * TT102 calls TT103 * TT16 calls TT103 * TT23 calls TT103
Draw a small set of crosshairs on a galactic chart at the coordinates in (QQ9, QQ10)..TT123 STA QQ19+4 \ Store the original coordinate in temporary storage at \ QQ19+4 CLC \ Set A = A + QQ19+3, so A now contains the original ADC QQ19+3 \ coordinate, moved by the delta LDX QQ19+3 \ If the delta is negative, jump to TT124 BMI TT124 BCC TT125 \ If the C flag is clear, then the above addition didn't \ overflow, so jump to TT125 to return the updated value RTS \ Otherwise the C flag is set and the above addition \ overflowed, so do not update the return value .TT124 BCC TT180 \ If the C flag is clear, then because the delta is \ negative, this indicates the addition (which is \ effectively a subtraction) underflowed, so jump to \ TT180 to return from the subroutine without updating \ the return value .TT125 STA QQ19+4 \ Store the updated coordinate in QQ19+4 .TT180 RTS \ Return from the subroutineName: TT123 [Show more] Type: Subroutine Category: Charts Summary: Move galactic coordinates by a signed deltaContext: See this subroutine on its own page References: This subroutine is called as follows: * TT16 calls TT123 * TT105 calls via TT180
Move an 8-bit galactic coordinate by a certain distance in either direction (i.e. a signed 8-bit delta), but only if it doesn't cause the coordinate to overflow. The coordinate is in a single axis, so it's either an x-coordinate or a y-coordinate.
Arguments: A The galactic coordinate to update QQ19+3 The delta (can be positive or negative)
Returns: QQ19+4 The updated coordinate after moving by the delta (this will be the same as A if moving by the delta overflows)
Other entry points: TT180 Contains an RTS.TT105 LDA QQ9 \ Set A = QQ9 - QQ0, the horizontal distance between the SEC \ crosshairs (QQ9) and the current system (QQ0) SBC QQ0 CMP #38 \ If the horizontal distance in A < 38, then the BCC TT179 \ crosshairs are close enough to the current system to \ appear in the Short-range Chart, so jump to TT179 to \ check the vertical distance CMP #230 \ If the horizontal distance in A < -26, then the BCC TT180 \ crosshairs are too far from the current system to \ appear in the Short-range Chart, so jump to TT180 to \ return from the subroutine (as TT180 contains an RTS) .TT179 ASL A \ Set QQ19 = 104 + A * 4 ASL A \ CLC \ 104 is the x-coordinate of the centre of the chart, ADC #104 \ so this sets QQ19 to the screen pixel x-coordinate STA QQ19 \ of the crosshairs LDA QQ10 \ Set A = QQ10 - QQ1, the vertical distance between the SEC \ crosshairs (QQ10) and the current system (QQ1) SBC QQ1 CMP #38 \ If the vertical distance in A is < 38, then the BCC P%+6 \ crosshairs are close enough to the current system to \ appear in the Short-range Chart, so skip the next two \ instructions CMP #220 \ If the horizontal distance in A is < -36, then the BCC TT180 \ crosshairs are too far from the current system to \ appear in the Short-range Chart, so jump to TT180 to \ return from the subroutine (as TT180 contains an RTS) ASL A \ Set QQ19+1 = 90 + A * 2 CLC \ ADC #90 \ 90 is the y-coordinate of the centre of the chart, STA QQ19+1 \ so this sets QQ19+1 to the screen pixel x-coordinate \ of the crosshairs LDA #8 \ Set QQ19+2 to 8 denote crosshairs of size 8 STA QQ19+2 JMP TT15 \ Jump to TT15 to draw crosshairs of size 8 at the \ crosshairs coordinates, returning from the subroutine \ using a tail callName: TT105 [Show more] Type: Subroutine Category: Charts Summary: Draw crosshairs on the Short-range Chart, with clippingContext: See this subroutine on its own page References: This subroutine is called as follows: * TT103 calls TT105
Check whether the crosshairs are close enough to the current system to appear on the Short-range Chart, and if so, draw them..TT23 LDA #128 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 128 (Short- \ range Chart) LDA #7 \ Move the text cursor to column 7 STA XC LDA #190 \ Print recursive token 30 ("SHORT RANGE CHART") and JSR NLIN3 \ draw a horizontal line at pixel row 19 to box in the \ title JSR TT14 \ Call TT14 to draw a circle with crosshairs at the \ current system's galactic coordinates JSR TT103 \ Draw small crosshairs at coordinates (QQ9, QQ10), \ i.e. at the selected system JSR TT81 \ Set the seeds in QQ15 to those of system 0 in the \ current galaxy (i.e. copy the seeds from QQ21 to QQ15) LDA #0 \ Set A = 0, which we'll use below to zero out the INWK \ workspace STA XX20 \ We're about to start working our way through each of \ the galaxy's systems, so set up a counter in XX20 for \ each system, starting at 0 and looping through to 255 LDX #24 \ First, though, we need to zero out the 25 bytes at \ INWK so we can use them to work out which systems have \ room for a label, so set a counter in X for 25 bytes .EE3 STA INWK,X \ Set the X-th byte of INWK to zero DEX \ Decrement the counter BPL EE3 \ Loop back to EE3 for the next byte until we've zeroed \ all 25 bytes \ We now loop through every single system in the galaxy \ and check the distance from the current system whose \ coordinates are in (QQ0, QQ1). We get the galactic \ coordinates of each system from the system's seeds, \ like this: \ \ x = s1_hi (which is stored in QQ15+3) \ y = s0_hi (which is stored in QQ15+1) \ \ so the following loops through each system in the \ galaxy in turn and calculates the distance between \ (QQ0, QQ1) and (s1_hi, s0_hi) to find the closest one .TT182 LDA QQ15+3 \ Set A = s1_hi - QQ0, the horizontal distance between SEC \ (s1_hi, s0_hi) and (QQ0, QQ1) SBC QQ0 STA XX12 \ Store the horizontal distance in XX12, so we can \ retrieve it later BCS TT184 \ If a borrow didn't occur, i.e. s1_hi >= QQ0, then the \ result is positive, so jump to TT184 and skip the \ following two instructions EOR #&FF \ Otherwise negate the result in A, so A is always ADC #1 \ positive (i.e. A = |s1_hi - QQ0|) .TT184 CMP #20 \ If the horizontal distance in A is >= 20, then this BCS TT187 \ system is too far away from the current system to \ appear in the Short-range Chart, so jump to TT187 to \ move on to the next system LDA QQ15+1 \ Set A = s0_hi - QQ1, the vertical distance between SEC \ (s1_hi, s0_hi) and (QQ0, QQ1) SBC QQ1 STA K4 \ Store the vertical distance in K4, so we can retrieve \ it later BCS TT186 \ If a borrow didn't occur, i.e. s0_hi >= QQ1, then the \ result is positive, so jump to TT186 and skip the \ following two instructions EOR #&FF \ Otherwise negate the result in A, so A is always ADC #1 \ positive (i.e. A = |s0_hi - QQ1|) .TT186 CMP #38 \ If the vertical distance in A is >= 38, then this BCS TT187 \ system is too far away from the current system to \ appear in the Short-range Chart, so jump to TT187 to \ move on to the next system \ This system should be shown on the Short-range Chart, \ so now we need to work out where the label should go, \ and set up the various variables we need to draw the \ system's filled circle on the chart LDA XX12 \ Retrieve the horizontal distance from XX12, so A now \ contains the horizontal distance between this system \ and the current system \ \ Let's call this the x-delta, as it's the horizontal \ difference between the current system at the centre of \ the chart, and this system (so A is negative if it's \ to the left of the chart's centre, or positive if it's \ to the right) ASL A \ Set XX12 = 104 + x-delta * 4 ASL A \ ADC #104 \ 104 is the x-coordinate of the centre of the chart, STA XX12 \ so this sets XX12 to the centre 104 +/- 76, the pixel \ x-coordinate of this system LSR A \ Move the text cursor to column x-delta / 2 + 1 LSR A \ which will be in the range 1-10 LSR A STA XC INC XC LDA K4 \ Retrieve the vertical distance from XX12, so A now \ contains the vertical distance between this system \ and the current system \ \ Let's call this the y-delta, as it's the vertical \ difference between the current system at the centre of \ the chart, and this system (so A is negative if it's \ above the chart's centre, or positive if it's below) ASL A \ Set K4 = 90 + y-delta * 2 ADC #90 \ STA K4 \ 90 is the y-coordinate of the centre of the chart, \ so this sets K4 to the centre 90 +/- 74, the pixel \ y-coordinate of this system LSR A \ Set Y = K4 / 8, so Y contains the number of the text LSR A \ row that contains this system LSR A TAY \ Now to see if there is room for this system's label. \ Ideally we would print the system name on the same \ text row as the system, but we only want to print one \ label per row, to prevent overlap, so now we check \ this system's row, and if that's already occupied, \ the row above, and if that's already occupied, the \ row below... and if that's already occupied, we give \ up and don't print a label for this system LDX INWK,Y \ If the value in INWK+Y is 0 (i.e. the text row BEQ EE4 \ containing this system does not already have another \ system's label on it), jump to EE4 to store this \ system's label on this row INY \ If the value in INWK+Y+1 is 0 (i.e. the text row below LDX INWK,Y \ the one containing this system does not already have BEQ EE4 \ another system's label on it), jump to EE4 to store \ this system's label on this row DEY \ If the value in INWK+Y-1 is 0 (i.e. the text row above DEY \ the one containing this system does not already have LDX INWK,Y \ another system's label on it), fall through into to BNE ee1 \ EE4 to store this system's label on this row, \ otherwise jump to ee1 to skip printing a label for \ this system (as there simply isn't room) .EE4 STY YC \ Now to print the label, so move the text cursor to row \ Y (which contains the row where we can print this \ system's label) CPY #3 \ If Y < 3, then the system would clash with the chart BCC TT187 \ title, so jump to TT187 to skip showing the system LDA #&FF \ Store &FF in INWK+Y, to denote that this row is now STA INWK,Y \ occupied so we don't try to print another system's \ label on this row LDA #%10000000 \ Set bit 7 of QQ17 to switch to Sentence Case STA QQ17 JSR cpl \ Call cpl to print out the system name for the seeds \ in QQ15 (which now contains the seeds for the current \ system) .ee1 LDA #0 \ Now to plot the star, so set the high bytes of K, K3 STA K3+1 \ and K4 to 0 STA K4+1 STA K+1 LDA XX12 \ Set the low byte of K3 to XX12, the pixel x-coordinate STA K3 \ of this system LDA QQ15+5 \ Fetch s2_hi for this system from QQ15+5, extract bit 0 AND #1 \ and add 2 to get the size of the star, which we store ADC #2 \ in K. This will be either 2, 3 or 4, depending on the STA K \ value of bit 0, and whether the C flag is set (which \ will vary depending on what happens in the above call \ to cpl). Incidentally, the planet's average radius \ also uses s2_hi, bits 0-3 to be precise, but that \ doesn't mean the two sizes affect each other \ We now have the following: \ \ K(1 0) = radius of star (2, 3 or 4) \ \ K3(1 0) = pixel x-coordinate of system \ \ K4(1 0) = pixel y-coordinate of system \ \ which we can now pass to the SUN routine to draw a \ small "sun" on the Short-range Chart for this system JSR FLFLLS \ Call FLFLLS to reset the LSO block JSR SUN \ Call SUN to plot a sun with radius K at pixel \ coordinate (K3, K4) JSR FLFLLS \ Call FLFLLS to reset the LSO block .TT187 JSR TT20 \ We want to move on to the next system, so call TT20 \ to twist the three 16-bit seeds in QQ15 INC XX20 \ Increment the counter BEQ TT111-1 \ If X = 0 then we have done all 256 systems, so return \ from the subroutine (as TT111-1 contains an RTS) JMP TT182 \ Otherwise jump back up to TT182 to process the next \ system.TT81 LDX #5 \ Set up a counter in X to copy six bytes (for three \ 16-bit numbers) LDA QQ21,X \ Copy the X-th byte in QQ21 to the X-th byte in QQ15 STA QQ15,X DEX \ Decrement the counter BPL TT81+2 \ Loop back up to the LDA instruction if we still have \ more bytes to copy RTS \ Return from the subroutineName: TT81 [Show more] Type: Subroutine Category: Universe Summary: Set the selected system's seeds to those of system 0Context: See this subroutine on its own page References: This subroutine is called as follows: * cour_buy calls TT81 * HME2 calls TT81 * TT111 calls TT81 * TT22 calls TT81 * TT23 calls TT81
Copy the three 16-bit seeds for the current galaxy's system 0 (QQ21) into the seeds for the selected system (QQ15) - in other words, set the selected system's seeds to those of system 0..TT111 JSR TT81 \ Set the seeds in QQ15 to those of system 0 in the \ current galaxy (i.e. copy the seeds from QQ21 to QQ15) \ We now loop through every single system in the galaxy \ and check the distance from (QQ9, QQ10). We get the \ galactic coordinates of each system from the system's \ seeds, like this: \ \ x = s1_hi (which is stored in QQ15+3) \ y = s0_hi (which is stored in QQ15+1) \ \ so the following loops through each system in the \ galaxy in turn and calculates the distance between \ (QQ9, QQ10) and (s1_hi, s0_hi) to find the closest one LDY #127 \ Set Y = T = 127 to hold the shortest distance we've STY T \ found so far, which we initially set to half the \ distance across the galaxy, or 127, as our coordinate \ system ranges from (0,0) to (255, 255) LDA #0 \ Set A = U = 0 to act as a counter for each system in STA U \ the current galaxy, which we start at system 0 and \ loop through to 255, the last system .TT130 LDA QQ15+3 \ Set A = s1_hi - QQ9, the horizontal distance between SEC \ (s1_hi, s0_hi) and (QQ9, QQ10) SBC QQ9 BCS TT132 \ If a borrow didn't occur, i.e. s1_hi >= QQ9, then the \ result is positive, so jump to TT132 and skip the \ following two instructions EOR #&FF \ Otherwise negate the result in A, so A is always ADC #1 \ positive (i.e. A = |s1_hi - QQ9|) .TT132 LSR A \ Set S = A / 2 STA S \ = |s1_hi - QQ9| / 2 LDA QQ15+1 \ Set A = s0_hi - QQ10, the vertical distance between SEC \ (s1_hi, s0_hi) and (QQ9, QQ10) SBC QQ10 BCS TT134 \ If a borrow didn't occur, i.e. s0_hi >= QQ10, then the \ result is positive, so jump to TT134 and skip the \ following two instructions EOR #&FF \ Otherwise negate the result in A, so A is always ADC #1 \ positive (i.e. A = |s0_hi - QQ10|) .TT134 LSR A \ Set A = S + A / 2 CLC \ = |s1_hi - QQ9| / 2 + |s0_hi - QQ10| / 2 ADC S \ \ So A now contains the sum of the horizontal and \ vertical distances, both divided by 2 so the result \ fits into one byte, and although this doesn't contain \ the actual distance between the systems, it's a good \ enough approximation to use for comparing distances CMP T \ If A >= T, then this system's distance is bigger than BCS TT135 \ our "minimum distance so far" stored in T, so it's no \ closer than the systems we have already found, so \ skip to TT135 to move on to the next system STA T \ This system is the closest to (QQ9, QQ10) so far, so \ update T with the new "distance" approximation LDX #5 \ As this system is the closest we have found yet, we \ want to store the system's seeds in case it ends up \ being the closest of all, so we set up a counter in X \ to copy six bytes (for three 16-bit numbers) .TT136 LDA QQ15,X \ Copy the X-th byte in QQ15 to the X-th byte in QQ19, STA QQ19,X \ where QQ15 contains the seeds for the system we just \ found to be the closest so far, and QQ19 is temporary \ storage DEX \ Decrement the counter BPL TT136 \ Loop back to TT136 if we still have more bytes to \ copy LDA U \ Store the system number U in ZZ, so when we are done STA ZZ \ looping through all the candidates, the winner's \ number will be in ZZ .TT135 JSR TT20 \ We want to move on to the next system, so call TT20 \ to twist the three 16-bit seeds in QQ15 INC U \ Increment the system counter in U BNE TT130 \ If U > 0 then we haven't done all 256 systems yet, so \ loop back up to TT130 \ We have now finished checking all the systems in the \ galaxy, and the seeds for the closest system are in \ QQ19, so now we want to copy these seeds to QQ15, \ to set the selected system to this closest system LDX #5 \ So we set up a counter in X to copy six bytes (for \ three 16-bit numbers) .TT137 LDA QQ19,X \ Copy the X-th byte in QQ19 to the X-th byte in QQ15 STA QQ15,X DEX \ Decrement the counter BPL TT137 \ Loop back to TT137 if we still have more bytes to \ copy LDA QQ15+1 \ The y-coordinate of the system described by the seeds STA QQ10 \ in QQ15 is in QQ15+1 (s0_hi), so we copy this to QQ10 \ as this is where we store the selected system's \ y-coordinate LDA QQ15+3 \ The x-coordinate of the system described by the seeds STA QQ9 \ in QQ15 is in QQ15+3 (s1_hi), so we copy this to QQ9 \ as this is where we store the selected system's \ x-coordinate \ We have now found the closest system to (QQ9, QQ10) \ and have set it as the selected system, so now we \ need to work out the distance between the selected \ system and the current system SEC \ Set A = QQ9 - QQ0, the horizontal distance between SBC QQ0 \ the selected system's x-coordinate (QQ9) and the \ current system's x-coordinate (QQ0) BCS TT139 \ If a borrow didn't occur, i.e. QQ9 >= QQ0, then the \ result is positive, so jump to TT139 and skip the \ following two instructions EOR #&FF \ Otherwise negate the result in A, so A is always ADC #1 \ positive (i.e. A = |QQ9 - QQ0|) \ A now contains the difference between the two \ systems' x-coordinates, with the sign removed. We \ will refer to this as the x-delta ("delta" means \ change or difference in maths) .TT139 JSR SQUA2 \ Set (A P) = A * A \ = |QQ9 - QQ0| ^ 2 \ = x_delta ^ 2 STA K+1 \ Store (A P) in K(1 0) LDA P STA K LDA QQ10 \ Set A = QQ10 - QQ1, the vertical distance between the SEC \ selected system's y-coordinate (QQ10) and the current SBC QQ1 \ system's y-coordinate (QQ1) BCS TT141 \ If a borrow didn't occur, i.e. QQ10 >= QQ1, then the \ result is positive, so jump to TT141 and skip the \ following two instructions EOR #&FF \ Otherwise negate the result in A, so A is always ADC #1 \ positive (i.e. A = |QQ10 - QQ1|) .TT141 LSR A \ Set A = A / 2 \ A now contains the difference between the two \ systems' y-coordinates, with the sign removed, and \ halved. We halve the value because the galaxy in \ in Elite is rectangular rather than square, and is \ twice as wide (x-axis) as it is high (y-axis), so to \ get a distance that matches the shape of the \ long-range galaxy chart, we need to halve the \ distance between the vertical y-coordinates. We will \ refer to this as the y-delta JSR SQUA2 \ Set (A P) = A * A \ = (|QQ10 - QQ1| / 2) ^ 2 \ = y_delta ^ 2 \ By this point we have the following results: \ \ K(1 0) = x_delta ^ 2 \ (A P) = y_delta ^ 2 \ \ so to find the distance between the two points, we \ can use Pythagoras - so first we need to add the two \ results together, and then take the square root PHA \ Store the high byte of the y-axis value on the stack, \ so we can use A for another purpose LDA P \ Set Q = P + K, which adds the low bytes of the two CLC \ calculated values ADC K STA Q PLA \ Restore the high byte of the y-axis value from the \ stack into A again ADC K+1 \ Set R = A + K+1, which adds the high bytes of the two STA R \ calculated values, so we now have: \ \ (R Q) = K(1 0) + (A P) \ = (x_delta ^ 2) + (y_delta ^ 2) JSR LL5 \ Set Q = SQRT(R Q), so Q now contains the distance \ between the two systems, in terms of coordinates \ We now store the distance to the selected system * 4 \ in the two-byte location QQ8, by taking (0 Q) and \ shifting it left twice, storing it in QQ8(1 0) LDA Q \ First we shift the low byte left by setting ASL A \ A = Q * 2, with bit 7 of A going into the C flag LDX #0 \ Now we set the high byte in QQ8+1 to 0 and rotate STX QQ8+1 \ the C flag into bit 0 of QQ8+1 ROL QQ8+1 ASL A \ And then we repeat the shift left of (QQ8+1 A) ROL QQ8+1 STA QQ8 \ And store A in the low byte, QQ8, so QQ8(1 0) now \ contains Q * 4. Given that the width of the galaxy is \ 256 in coordinate terms, the width of the galaxy \ would be 1024 in the units we store in QQ8 JMP TT24 \ Call TT24 to calculate system data from the seeds in \ QQ15 and store them in the relevant locations, so our \ new selected system is fully set up, and return from \ the subroutine using a tail callName: TT111 [Show more] Type: Subroutine Category: Universe Summary: Set the current system to the nearest system to a pointContext: See this subroutine on its own page References: This subroutine is called as follows: * ESCAPE calls TT111 * Ghy calls TT111 * hm calls TT111 * HME2 calls TT111 * hyp calls TT111 * hyp1 calls TT111 * Main flight loop (Part 3 of 16) calls TT111 * STATUS calls TT111 * TT102 calls TT111 * TT110 calls TT111 * TT23 calls via TT111-1
Given a set of galactic coordinates in (QQ9, QQ10), find the nearest system to this point in the galaxy, and set this as the currently selected system.
Arguments: QQ9 The x-coordinate near which we want to find a system QQ10 The y-coordinate near which we want to find a system
Returns: QQ8(1 0) The distance from the current system to the nearest system to the original coordinates QQ9 The x-coordinate of the nearest system to the original coordinates QQ10 The y-coordinate of the nearest system to the original coordinates QQ15 to QQ15+5 The three 16-bit seeds of the nearest system to the original coordinates ZZ The system number of the nearest system
Other entry points: TT111-1 Contains an RTS.jmp LDA QQ9 \ Set the current system's galactic x-coordinate to the STA QQ0 \ x-coordinate of the selected system LDA QQ10 \ Set the current system's galactic y-coordinate to the STA QQ1 \ y-coordinate of the selected system .hy5 RTS \ Return from the subroutineName: jmp [Show more] Type: Subroutine Category: Universe Summary: Set the current system to the selected systemContext: See this subroutine on its own page References: This subroutine is called as follows: * ESCAPE calls jmp * Ghy calls jmp * hyp1 calls jmp * hyp1_FLIGHT calls jmp
Returns: (QQ0, QQ1) The galactic coordinates of the new system
Other entry points: hy5 Contains an RTS.pr6 CLC \ Do not display a decimal point when printing \ Fall through into pr5 to print X to 5 digitsName: pr6 [Show more] Type: Subroutine Category: Text Summary: Print 16-bit number, left-padded to 5 digits, no pointContext: See this subroutine on its own page References: This subroutine is called as follows: * ee3 calls pr6 * TT25 calls pr6
Print the 16-bit number in (Y X) to 5 digits, left-padding with spaces for numbers with fewer than 3 digits (so numbers < 10000 are right-aligned), with no decimal point.
Arguments: X The low byte of the number to print Y The high byte of the number to print.pr5 LDA #5 \ Set the number of digits to print to 5 JMP TT11 \ Call TT11 to print (Y X) to 5 digits and return from \ the subroutine using a tail callName: pr5 [Show more] Type: Subroutine Category: Text Summary: Print a 16-bit number, left-padded to 5 digits, and optional pointContext: See this subroutine on its own page References: This subroutine is called as follows: * TT146 calls pr5 * TT151 calls pr5 * TT25 calls pr5
Print the 16-bit number in (Y X) to 5 digits, left-padding with spaces for numbers with fewer than 3 digits (so numbers < 10000 are right-aligned). Optionally include a decimal point.
Arguments: X The low byte of the number to print Y The high byte of the number to print C flag If set, include a decimal point.prq JSR TT27 \ Print the text token in A LDA #'?' \ Print a question mark and return from the JMP TT27 \ subroutine using a tail callName: prq [Show more] Type: Subroutine Category: Text Summary: Print a text token followed by a question markContext: See this subroutine on its own page References: This subroutine is called as follows: * cour_buy calls prq * eq calls prq * EQSHP calls prq * n_buyship calls prq * NWDAV4 calls prq * qv calls prq * TT147 calls prq * TT219 calls prq
Arguments: A The text token to be printed
Other entry points: prq+3 Print a question mark.TT151 PHA \ Store the item number on the stack and in QQ19+4 STA QQ19+4 ASL A \ Store the item number * 4 in QQ19, so this will act as ASL A \ an index into the market prices table at QQ23 for this STA QQ19 \ item (as there are four bytes per item in the table) LDA #1 \ Move the text cursor to column 1, for the item's name STA XC PLA \ Restore the item number ADC #208 \ Print recursive token 48 + A, which will be in the JSR TT27 \ range 48 ("FOOD") to 64 ("ALIEN ITEMS"), so this \ prints the item's name LDA #14 \ Move the text cursor to column 14, for the price STA XC LDX QQ19 \ Fetch byte #1 from the market prices table (units and LDA QQ23+1,X \ economic_factor) for this item and store in QQ19+1 STA QQ19+1 LDA QQ26 \ Fetch the random number for this system visit and AND QQ23+3,X \ AND with byte #3 from the market prices table (mask) \ to give: \ \ A = random AND mask CLC \ Add byte #0 from the market prices table (base_price), ADC QQ23,X \ so we now have: STA QQ24 \ \ A = base_price + (random AND mask) JSR TT152 \ Call TT152 to print the item's unit ("t", "kg" or \ "g"), padded to a width of two characters JSR var \ Call var to set QQ19+3 = economy * |economic_factor| \ (and set the availability of alien items to 0) LDA QQ19+1 \ Fetch the byte #1 that we stored above and jump to BMI TT155 \ TT155 if it is negative (i.e. if the economic_factor \ is negative) LDA QQ24 \ Set A = QQ24 + QQ19+3 ADC QQ19+3 \ \ = base_price + (random AND mask) \ + (economy * |economic_factor|) \ \ which is the result we want, as the economic_factor \ is positive JMP TT156 \ Jump to TT156 to multiply the result by 4 .TT155 LDA QQ24 \ Set A = QQ24 - QQ19+3 SEC \ SBC QQ19+3 \ = base_price + (random AND mask) \ - (economy * |economic_factor|) \ \ which is the result we want, as economic_factor \ is negative .TT156 STA QQ24 \ Store the result in QQ24 and P STA P LDA #0 \ Set A = 0 and call GC2 to calculate (Y X) = (A P) * 4, JSR GC2 \ which is the same as (Y X) = P * 4 because A = 0 SEC \ We now have our final price, * 10, so we can call pr5 JSR pr5 \ to print (Y X) to 5 digits, including a decimal \ point, as the C flag is set LDY QQ19+4 \ We now move on to availability, so fetch the market \ item number that we stored in QQ19+4 at the start LDA #5 \ Set A to 5 so we can print the availability to 5 \ digits (right-padded with spaces) LDX AVL,Y \ Set X to the item's availability, which is given in \ the AVL table STX QQ25 \ Store the availability in QQ25 CLC \ Clear the C flag BEQ TT172 \ If none are available, jump to TT172 to print a tab \ and a "-" JSR pr2+2 \ Otherwise print the 8-bit number in X to 5 digits, \ right-aligned with spaces. This works because we set \ A to 5 above, and we jump into the pr2 routine just \ after the first instruction, which would normally \ set the number of digits to 3 JMP TT152 \ Print the unit ("t", "kg" or "g") for the market item, \ with a following space if required to make it two \ characters long, and return from the subroutine using \ a tail call .TT172 LDA XC \ Move the text cursor in XC to the right by 4 columns, ADC #4 \ so the cursor is where the last digit would be if we STA XC \ were printing a 5-digit availability number LDA #'-' \ Print a "-" character by jumping to TT162+2, which BNE TT162+2 \ contains JMP TT27 (this BNE is effectively a JMP as A \ will never be zero), and return from the subroutine \ using a tail callName: TT151 [Show more] Type: Subroutine Category: Market Summary: Print the name, price and availability of a market item Deep dive: Market item prices and availability Galaxy and system seedsContext: See this subroutine on its own page References: This subroutine is called as follows: * TT167 calls TT151 * TT210 calls TT151 * TT219 calls TT151
Arguments: A The number of the market item to print, 0-16 (see QQ23 for details of item numbers)
Returns: QQ19+1 Byte #1 from the market prices table for this item QQ24 The item's price / 4 QQ25 The item's availability.TT152 LDA QQ19+1 \ Fetch the economic_factor from QQ19+1 AND #96 \ If bits 5 and 6 are both clear, jump to TT160 to BEQ TT160 \ print "t" for tonne, followed by a space, and return \ from the subroutine using a tail call CMP #32 \ If bit 5 is set, jump to TT161 to print "kg" for BEQ TT161 \ kilograms, and return from the subroutine using a tail \ call JSR TT16a \ Otherwise call TT16a to print "g" for grams, and fall \ through into TT162 to print a space and return from \ the subroutineName: TT152 [Show more] Type: Subroutine Category: Market Summary: Print the unit ("t", "kg" or "g") for a market itemContext: See this subroutine on its own page References: This subroutine is called as follows: * TT151 calls TT152 * TT210 calls TT152 * TT219 calls TT152
Print the unit ("t", "kg" or "g") for the market item whose byte #1 from the market prices table is in QQ19+1, right-padded with spaces to a width of two characters (so that's "t ", "kg" or "g ")..TT162 LDA #' ' \ Load a space character into A JMP TT27 \ Print the text token in A and return from the \ subroutine using a tail callName: TT162 [Show more] Type: Subroutine Category: Text Summary: Print a spaceContext: See this subroutine on its own page References: This subroutine is called as follows: * cour_count calls TT162 * dn calls TT162 * EQSHP calls TT162 * menu calls TT162 * n_buyship calls TT162 * spc calls TT162 * TT160 calls TT162 * TT219 calls TT162 * TT25 calls TT162 * TTX66 calls TT162 * TT151 calls via TT162+2 * TT163 calls via TT162+2
Other entry points: TT162+2 Jump to TT27 to print the text token in A.TT160 LDA #'t' \ Load a "t" character into A JSR TT26 \ Print the character, using TT216 so that it doesn't \ change the character case BCC TT162 \ Jump to TT162 to print a space and return from the \ subroutine using a tail call (this BCC is effectively \ a JMP as the C flag is cleared by TT26).TT161 LDA #'k' \ Load a "k" character into A JSR TT26 \ Print the character, using TT216 so that it doesn't \ change the character case, and fall through into \ TT16a to print a "g" characterName: TT161 [Show more] Type: Subroutine Category: Market Summary: Print "kg" (for kilograms)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT152 calls TT161.TT16a LDA #'g' \ Load a "g" character into A JMP TT26 \ Print the character, using TT216 so that it doesn't \ change the character case, and return from the \ subroutine using a tail callName: TT16a [Show more] Type: Subroutine Category: Market Summary: Print "g" (for grams)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT152 calls TT16a.TT163 LDA #17 \ Move the text cursor in XC to column 17 STA XC LDA #255 \ Print recursive token 95 token ("UNIT QUANTITY BNE TT162+2 \ {crlf} PRODUCT UNIT PRICE FOR SALE{crlf}{lf}") by \ jumping to TT162+2, which contains JMP TT27 (this BNE \ is effectively a JMP as A will never be zero), and \ return from the subroutine using a tail callName: TT163 [Show more] Type: Subroutine Category: Market Summary: Print the headers for the table of market pricesContext: See this subroutine on its own page References: This subroutine is called as follows: * TT167 calls TT163 * TT219 calls TT163
Print the column headers for the prices table in the Buy Cargo and Market Price screens..TT167 LDA #16 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 16 (Market \ Price screen) LDA #5 \ Move the text cursor to column 5 STA XC LDA #167 \ Print recursive token 7 ("{current system name} MARKET JSR NLIN3 \ PRICES") and draw a horizontal line at pixel row 19 \ to box in the title LDA #3 \ Move the text cursor to row 3 STA YC JSR TT163 \ Print the column headers for the prices table LDA #0 \ We're going to loop through all the available market STA QQ29 \ items, so we set up a counter in QQ29 to denote the \ current item and start it at 0 .TT168 LDX #%10000000 \ Set bit 7 of QQ17 to switch to Sentence Case, with the STX QQ17 \ next letter in capitals JSR TT151 \ Call TT151 to print the item name, market price and \ availability of the current item, and set QQ24 to the \ item's price / 4, QQ25 to the quantity available and \ QQ19+1 to byte #1 from the market prices table for \ this item INC YC \ Move the text cursor down one row INC QQ29 \ Increment QQ29 to point to the next item LDA QQ29 \ If QQ29 >= 17 then jump to TT168 as we have done the CMP #17 \ last item BCC TT168 RTS \ Return from the subroutineName: TT167 [Show more] Type: Subroutine Category: Market Summary: Show the Market Price screen (red key f7)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls TT167.var LDA QQ19+1 \ Extract bits 0-5 from QQ19+1 into A, to get the AND #31 \ economic_factor without its sign, in other words: \ \ A = |economic_factor| LDY QQ28 \ Set Y to the economy byte of the current system STA QQ19+2 \ Store A in QQ19+2 CLC \ Clear the C flag so we can do additions below LDA #0 \ Set AVL+16 (availability of alien items) to 0, STA AVL+16 \ setting A to 0 in the process .TT153 \ We now do the multiplication by doing a series of \ additions in a loop, building the result in A. Each \ loop adds QQ19+2 (|economic_factor|) to A, and it \ loops the number of times given by the economy byte; \ in other words, because A starts at 0, this sets: \ \ A = economy * |economic_factor| DEY \ Decrement the economy in Y, exiting the loop when it BMI TT154 \ becomes negative ADC QQ19+2 \ Add QQ19+2 to A JMP TT153 \ Loop back to TT153 to do another addition .TT154 STA QQ19+3 \ Store the result in QQ19+3 RTS \ Return from the subroutineName: var [Show more] Type: Subroutine Category: Market Summary: Calculate QQ19+3 = economy * |economic_factor|Context: See this subroutine on its own page References: This subroutine is called as follows: * GVL calls var * TT151 calls var
Set QQ19+3 = economy * |economic_factor|, given byte #1 of the market prices table for an item. Also sets the availability of alien items to 0. This routine forms part of the calculations for market item prices (TT151) and availability (GVL).
Arguments: QQ19+1 Byte #1 of the market prices table for this market item (which contains the economic_factor in bits 0-5, and the sign of the economic_factor in bit 7).hyp1 JSR TT111 \ Select the system closest to galactic coordinates \ (QQ9, QQ10) JSR jmp \ Set the current system to the selected system LDX #5 \ We now want to copy the seeds for the selected system \ in QQ15 into QQ2, where we store the seeds for the \ current system, so set up a counter in X for copying \ 6 bytes (for three 16-bit seeds) .TT112 LDA QQ15,X \ Copy the X-th byte in QQ15 to the X-th byte in QQ2, to STA QQ2,X \ update the selected system to the new one. Note that \ this approach has a minor bug associated with it: if \ your hyperspace counter hits 0 just as you're docking, \ then you will magically appear in the station in your \ hyperspace destination, without having to go to the \ effort of actually flying there. This bug was fixed in \ later versions by saving the destination seeds in a \ separate location called safehouse, and using those \ instead... but that isn't the case in this version DEX \ Decrement the counter BPL TT112 \ Loop back to TT112 if we still have more bytes to \ copy INX \ Set X = 0 (as we ended the above loop with X = &FF) STX EV \ Set EV, the extra vessels spawning counter, to 0, as \ we are entering a new system with no extra vessels \ spawned LDA QQ3 \ Set the current system's economy in QQ28 to the STA QQ28 \ selected system's economy from QQ3 LDA QQ5 \ Set the current system's tech level in tek to the STA tek \ selected system's economy from QQ5 LDA QQ4 \ Set the current system's government in gov to the STA gov \ selected system's government from QQ4 RTS \ Return from the subroutineName: hyp1 [Show more] Type: Subroutine Category: Universe Summary: Process a jump to the system closest to (QQ9, QQ10)Context: See this subroutine on its own page References: This subroutine is called as follows: * BR1 (Part 2 of 2) calls hyp1
Do a hyperspace jump to the system closest to galactic coordinates (QQ9, QQ10), and set up the current system's state to those of the new system.
Returns: (QQ0, QQ1) The galactic coordinates of the new system QQ2 to QQ2+6 The seeds of the new system EV Set to 0 QQ28 The new system's economy tek The new system's tech level gov The new system's government
Other entry points: hyp1+3 Jump straight to the system at (QQ9, QQ10) without first calculating which system is closest. We do this if we already know that (QQ9, QQ10) points to a system.LCASH STX T1 \ Subtract the least significant bytes: LDA CASH+3 \ SEC \ CASH+3 = CASH+3 - X SBC T1 STA CASH+3 STY T1 \ Then the second most significant bytes: LDA CASH+2 \ SBC T1 \ CASH+2 = CASH+2 - Y STA CASH+2 LDA CASH+1 \ Then the third most significant bytes (which are 0): SBC #0 \ STA CASH+1 \ CASH+1 = CASH+1 - 0 LDA CASH \ And finally the most significant bytes (which are 0): SBC #0 \ STA CASH \ CASH = CASH - 0 BCS TT113 \ If the C flag is set then the subtraction didn't \ underflow, so the value in CASH is correct and we can \ jump to TT113 to return from the subroutine with the \ C flag set to indicate success (as TT113 contains an \ RTS) \ Otherwise we didn't have enough cash in CASH to \ subtract (Y X) from it, so fall through into \ MCASH to reverse the sum and restore the original \ value in CASH, and returning with the C flag clearName: LCASH [Show more] Type: Subroutine Category: Maths (Arithmetic) Summary: Subtract an amount of cash from the cash potContext: See this subroutine on its own page References: This subroutine is called as follows: * cour_buy calls LCASH * eq calls LCASH * stay_here calls LCASH * TT219 calls LCASH
Subtract (Y X) cash from the cash pot in CASH, but only if there is enough cash in the pot. As CASH is a four-byte number, this calculates: CASH(0 1 2 3) = CASH(0 1 2 3) - (0 0 Y X)
Returns: C flag If set, there was enough cash to do the subtraction If clear, there was not enough cash to do the subtraction.MCASH TXA \ Add the least significant bytes: CLC \ ADC CASH+3 \ CASH+3 = CASH+3 + X STA CASH+3 TYA \ Then the second most significant bytes: ADC CASH+2 \ STA CASH+2 \ CASH+2 = CASH+2 + Y LDA CASH+1 \ Then the third most significant bytes (which are 0): ADC #0 \ STA CASH+1 \ CASH+1 = CASH+1 + 0 LDA CASH \ And finally the most significant bytes (which are 0): ADC #0 \ STA CASH \ CASH = CASH + 0 CLC \ Clear the C flag, so if the above was done following \ a failed LCASH call, the C flag correctly indicates \ failure .TT113 RTS \ Return from the subroutineName: MCASH [Show more] Type: Subroutine Category: Maths (Arithmetic) Summary: Add an amount of cash to the cash potContext: See this subroutine on its own page References: This subroutine is called as follows: * cour_dock calls MCASH * DEBRIEF calls MCASH * EQSHP calls MCASH * Main flight loop (Part 12 of 16) calls MCASH * status_equip calls MCASH * TT210 calls MCASH * LCASH calls via TT113
Add (Y X) cash to the cash pot in CASH. As CASH is a four-byte number, this calculates: CASH(0 1 2 3) = CASH(0 1 2 3) + (Y X)
Other entry points: TT113 Contains an RTS.GCASH JSR MULTU \ Call MULTU to calculate (A P) = P * QName: GCASH [Show more] Type: Subroutine Category: Maths (Arithmetic) Summary: Calculate (Y X) = P * Q * 4Context: See this subroutine on its own page References: This subroutine is called as follows: * TT219 calls GCASH
Calculate the following multiplication of unsigned 8-bit numbers: (Y X) = P * Q * 4.GC2 ASL P \ Set (A P) = (A P) * 4 ROL A ASL P ROL A .price_xy TAY \ Set (Y X) = (A P) LDX P RTS \ Return from the subroutineName: GC2 [Show more] Type: Subroutine Category: Maths (Arithmetic) Summary: Calculate (Y X) = (A P) * 4Context: See this subroutine on its own page References: This subroutine is called as follows: * TT151 calls GC2 * TT210 calls via price_xy
Calculate the following multiplication of unsigned 16-bit numbers: (Y X) = (A P) * 4
Other entry points: price_xy Set (Y X) = (A P).update_pod LDA #&8F \ Send command &8F to the I/O processor: JSR tube_write \ \ write_pod(escp, hfx) \ \ which will update the values of ESCP and HFX in the \ I/O processor, so the palette gets set correctly for \ the dashboard (ESCP) and hyperspace tunnel (HFX) LDA ESCP \ Send the first parameter to the I/O processor: JSR tube_write \ \ * escp = ESCP LDA HFX \ Send the second parameter to the I/O processor: JMP tube_write \ \ * hfx = HFX \ \ and return from the subroutine using a tail callName: update_pod [Show more] Type: Subroutine Category: Dashboard Summary: Ensure the correct palette is shown for the dashboard/hyperspace tunnel, by sending a write_pod command to the I/O processorContext: See this subroutine on its own page References: This subroutine is called as follows: * DFAULT calls update_pod * EQSHP calls update_pod * ESCAPE calls update_pod * LL164 calls update_pod * n_buyship calls update_pod * status_equip calls update_pod.EQSHP LDA #32 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 32 (Equip \ Ship screen) JSR FLKB \ Flush the keyboard buffer LDA #12 \ Move the text cursor to column 12 STA XC LDA #207 \ Print recursive token 47 ("EQUIP") followed by a space JSR spc LDA #185 \ Print recursive token 25 ("SHIP") and draw a JSR NLIN3 \ horizontal line at pixel row 19 to box in the title LDA #%10000000 \ Set bit 7 of QQ17 to switch to Sentence Case, with the STA QQ17 \ next letter in capitals INC YC \ Move the text cursor down one line JSR CTRL \ Scan the keyboard to see if CTRL is currently pressed, \ returning a negative value in A if it is BPL n_eqship \ If CTRL is not being pressed, jump down to n_eqship to \ keep processing the Equip Ship screen JMP n_buyship \ CTRL is being pressed, which means CTRL-f3 is being \ pressed, so jump to n_buyship to show the Buy Ship \ screen instead .bay JMP BAY \ Go to the docking bay (i.e. show the Status Mode \ screen) .n_eqship LDA tek \ Fetch the tech level of the current system from tek CLC \ and add 2 (the tech level is stored as 0-14, so A is ADC #2 \ now set to between 2 and 16) CMP #12 \ If A >= 12 then set A = 14, so A is now set to between BCC P%+4 \ 2 and 14 LDA #14 STA Q \ Set QQ25 = A (so QQ25 is in the range 2-14 and STA QQ25 \ represents number of the most advanced item available INC Q \ in this system, which we can pass to gnum below when \ asking which item we want to buy) \ \ Set Q = A + 1 (so Q is in the range 3-15 and contains \ QQ25 + 1, i.e. the highest item number on sale + 1) LDA new_range \ Set A = new_range - QQ14, where QQ14 contains the SEC \ current fuel in light years * 10, so this leaves the SBC QQ14 \ amount of fuel we need to fill 'er up (in light years \ * 10) ASL A \ The price of fuel is always 2 Cr per light year, so we STA PRXS \ double A and store it in PRXS, as the first price in \ the price list (which is reserved for fuel), and \ because the table contains prices as price * 10, it's \ in the right format (so tank containing 7.0 light \ years of fuel would be 14.0 Cr, or a PRXS value of \ 140) LDA #0 \ As the maximum amount of fuel in Elite-A can be more ROL A \ than 25.5 light years, we need to use PRXS(1 0) to STA PRXS+1 \ store the fuel level, so this catches bit 7 from the \ left shift of the low byte above (which the ASL will \ have put into the C flag), and sets bit 0 of the high \ byte in PRXS+1 accordingly LDX #1 \ We are now going to work our way through the equipment \ price list at PRXS, printing out the equipment that is \ available at this station, so set a counter in X, \ starting at 1, to hold the number of the current item \ plus 1 (so the item number in X loops through 1-13) .EQL1 STX XX13 \ Store the current item number + 1 in XX13 JSR TT67 \ Print a newline LDX XX13 \ Print the current item number + 1 to 3 digits, left- CLC \ padding with spaces, and with no decimal point, so the JSR pr2 \ items are numbered from 1 JSR TT162 \ Print a space LDA XX13 \ Print recursive token 104 + XX13, which will be in the CLC \ range 105 ("FUEL") to 116 ("GALACTIC HYPERSPACE ") ADC #104 \ so this prints the current item's name JSR TT27 LDA XX13 \ Call prx-3 to set (Y X) to the price of the item with JSR prx-3 \ number XX13 - 1 (as XX13 contains the item number + 1) SEC \ Set the C flag so we will print a decimal point when \ we print the price LDA #25 \ Move the text cursor to column 25 STA XC LDA #6 \ Print the number in (Y X) to 6 digits, left-padding JSR TT11 \ with spaces and including a decimal point, which will \ be the correct price for this item as (Y X) contains \ the price * 10, so the trailing zero will go after the \ decimal point (i.e. 5250 will be printed as 525.0) LDX XX13 \ Increment the current item number in XX13 INX CPX Q \ If X < Q, loop back up to print the next item on the BCC EQL1 \ list of equipment available at this station JSR CLYNS \ Clear the bottom three text rows of the upper screen, \ and move the text cursor to the first cleared row LDA #127 \ Print recursive token 127 ("ITEM") followed by a JSR prq \ question mark JSR gnum \ Call gnum to get a number from the keyboard, which \ will be the number of the item we want to purchase, \ returning the number entered in A and R, and setting \ the C flag if the number is bigger than the highest \ item number in QQ25 BEQ bay \ If no number was entered, jump up to bay to go to the \ docking bay (i.e. show the Status Mode screen) BCS bay \ If the number entered was too big, jump up to bay to \ go to the docking bay (i.e. show the Status Mode \ screen) SBC #0 \ Set A to the number entered - 1 (because the C flag is \ clear), which will be the actual item number we want \ to buy LDX #2 \ Move the text cursor to column 2 STX XC INC YC \ Move the text cursor down one line PHA \ Store A on the stack so we can restore it after the \ following code CMP #2 \ If A < 2, then we are buying fuel or missiles, so jump BCC equip_space \ down to equip_space to skip the checks for whether we \ have enough free space in the hold (as fuel and \ missiles don't take up hold space) LDA QQ20+16 \ Fetch the number of alien items in the hold into A, so \ the following call to Tml will include these in the \ total SEC \ Call Tml with X = 12 and the C flag set, to work out LDX #12 \ if there is space for one more tonne in the hold JSR Tml BCC equip_isspace \ If the C flag is clear then there is indeed room for \ another tonne, so jump to equip_isspace so we can buy \ the new piece of equipment LDA #14 \ Otherwise there isn't room in the hold for any more \ equipment, so set A to the value for recursive token \ 14 ("UNIT") JMP query_beep \ Print the recursive token given in A followed by a \ question mark, then make a beep, pause and go to the \ docking bay (i.e. show the Status Mode screen) .equip_isspace DEC new_hold \ We are now going to buy the piece of equipment, so \ decrement the free space in the hold, as equipment \ takes up hold space in Elite-A PLA \ Set A to the value from the top of the stack (so it PHA \ contains the number of the item we want to buy) .equip_space JSR eq \ Call eq to subtract the price of the item we want to \ buy (which is in A) from our cash pot, but only if we \ have enough cash in the pot. If we don't have enough \ cash, exit to the docking bay (i.e. show the Status \ Mode screen) PLA \ Restore A from the stack BNE et0 \ If A is not 0 (i.e. the item we've just bought is not \ fuel), skip to et0 LDX new_range \ Set the current fuel level in QQ14 to our current STX QQ14 \ ship's maximum hyperspace range from new_range, so the \ tank is now full JSR DIALS \ Call DIALS to update the dashboard with the new fuel \ level LDA #0 \ Set A to 0 as the call to DIALS will have overwritten \ the original value, and we still need it set \ correctly so we can continue through the conditional \ statements for all the other equipment .et0 CMP #1 \ If A is not 1 (i.e. the item we've just bought is not BNE et1 \ a missile), skip to et1 LDX NOMSL \ Fetch the current number of missiles from NOMSL into X INX \ Increment X to the new number of missiles LDY #124 \ Set Y to recursive token 124 ("ALL") CPX new_missiles \ If buying this missile would give us more than the BCS pres+3 \ maximum number of missiles that our current ship can \ hold (which is stored in new_missiles), jump to pres+3 \ to show the error "All Present", do not free up any \ space in the hold (as missiles do not take up hold \ space), beep and exit to the docking bay (i.e. show \ the Status Mode screen) STX NOMSL \ Otherwise update the number of missiles in NOMSL JSR msblob \ Reset the dashboard's missile indicators so none of \ them are targeted .et1 LDY #107 \ Set Y to recursive token 107 ("I.F.F.SYSTEM") CMP #2 \ If A is not 2 (i.e. the item we've just bought is not BNE et2 \ an I.F.F. system), skip to et2 LDX CRGO \ If we already have an I.F.F. system fitted (i.e. CRGO BNE pres \ is non-zero), jump to pres to show the error "I.F.F. \ System Present", beep and exit to the docking bay \ (i.e. show the Status Mode screen) DEC CRGO \ Otherwise we just scored ourselves an I.F.F. system, \ so set CRGO to &FF (as CRGO was 0 before the DEC \ instruction) .et2 CMP #3 \ If A is not 3 (i.e. the item we've just bought is not BNE et3 \ an E.C.M. system), skip to et3 INY \ Increment Y to recursive token 108 ("E.C.M.SYSTEM") LDX ECM \ If we already have an E.C.M. fitted (i.e. ECM is BNE pres \ non-zero), jump to pres to show the error "E.C.M. \ System Present", beep and exit to the docking bay \ (i.e. show the Status Mode screen) DEC ECM \ Otherwise we just took delivery of a brand new E.C.M. \ system, so set ECM to &FF (as ECM was 0 before the DEC \ instruction) .et3 CMP #4 \ If A is not 4 (i.e. the item we've just bought is not BNE et4 \ an extra pulse laser), skip to et4 LDY new_pulse \ Set Y to the power level of pulse lasers when fitted \ to our current ship type BNE equip_leap \ Jump to equip_merge (via equip_leap) to install the \ new laser (this BNE is effectively a JMP as Y is never \ zero) .et4 CMP #5 \ If A is not 5 (i.e. the item we've just bought is not BNE et5 \ an extra beam laser), skip to et5 LDY new_beam \ Set Y to the power level of beam lasers when fitted to \ our current ship type .equip_leap BNE equip_frog \ Jump to equip_merge (via equip_frog) to install the \ new laser (this BNE is effectively a JMP as Y is never \ zero) .et5 LDY #111 \ Set Y to recursive token 107 ("FUEL SCOOPS") CMP #6 \ If A is not 6 (i.e. the item we've just bought is not BNE et6 \ a fuel scoop), skip to et6 LDX BST \ If we already have fuel scoops fitted (i.e. BST is BEQ ed9 \ zero), jump to ed9, otherwise fall through into pres \ to show the error "Fuel Scoops Present", beep and \ exit to the docking bay (i.e. show the Status Mode \ screen) .pres \ If we get here we need to show an error to say that \ the item whose name is in recursive token Y is already \ present, and then process a refund for the cost of \ item number A INC new_hold \ We can't buy the requested equipment, so increment the \ free space in the hold, as we decremented it earlier \ in anticipation of making a deal, but the deal has \ fallen through STY K \ Store the item's name in K JSR prx \ Call prx to set (Y X) to the price of equipment item \ number A JSR MCASH \ Add (Y X) cash to the cash pot in CASH, as the station \ already took the money for this item in the JSR eq \ instruction above, but we can't fit the item, so need \ our money back LDA K \ Print the recursive token in K (the item's name) JSR spc \ followed by a space LDA #31 \ Print recursive token 145 ("PRESENT") JSR TT27 .err JSR dn2 \ Call dn2 to make a short, high beep and delay for 1 \ second JMP BAY \ Jump to BAY to go to the docking bay (i.e. show the \ Status Mode screen) .ed9 DEC BST \ We just bought a shiny new fuel scoop, so set BST to \ &FF (as BST was 0 before the jump to ed9 above) .et6 INY \ Increment Y to recursive token 112 ("E.C.M.SYSTEM") CMP #7 \ If A is not 7 (i.e. the item we've just bought is not BNE et7 \ an escape pod), skip to et7 LDX ESCP \ If we already have an escape pod fitted (i.e. ESCP is BNE pres \ non-zero), jump to pres to show the error "Escape Pod \ Present", beep and exit to the docking bay (i.e. show \ the Status Mode screen) DEC ESCP \ Otherwise we just bought an escape pod, so set ESCP \ to &FF (as ESCP was 0 before the DEC instruction) JSR update_pod \ Update the dashboard colours to reflect that we now \ have an escape pod .et7 INY \ Increment Y to recursive token 113 ("HYPERSPACE UNIT") CMP #8 \ If A is not 8 (i.e. the item we've just bought is not BNE et8 \ a hyperspace unit), skip to et8 LDX BOMB \ If we already have a hyperspace unit fitted (i.e. BOMB BNE pres \ is non-zero), jump to pres to show the error \ "Hyperspace Unit Present", beep and exit to the \ docking bay (i.e. show the Status Mode screen) DEC BOMB \ Otherwise we just bought an energy bomb, so set BOMB \ to &FF (as BOMB was 0 before the DEC instruction) .et8 INY \ Increment Y to recursive token 114 ("ENERGY UNIT") CMP #9 \ If A is not 9 (i.e. the item we've just bought is not BNE etA \ an energy unit), skip to etA LDX ENGY \ If we already have an energy unit fitted (i.e. ENGY is BNE pres \ non-zero), jump to pres to show the error "Energy Unit \ Present", beep and exit to the docking bay (i.e. show \ the Status Mode screen) LDX new_energy \ Otherwise we just picked up an energy unit, so set STX ENGY \ ENGY to new_energy, which is the value of our current \ ship's ship energy refresh rate with an energy unit \ fitted .etA INY \ Increment Y to recursive token 115 ("DOCKING \ COMPUTERS") CMP #10 \ If A is not 10 (i.e. the item we've just bought is not BNE etB \ a docking computer), skip to etB LDX DKCMP \ If we already have a docking computer fitted (i.e. BNE pres \ DKCMP is non-zero), jump to pres to show the error \ "Docking Computer Present", beep and exit to the \ docking bay (i.e. show the Status Mode screen) DEC DKCMP \ Otherwise we just got hold of a docking computer, so \ set DKCMP to &FF (as DKCMP was 0 before the DEC \ instruction) .etB INY \ Increment Y to recursive token 116 ("GALACTIC \ HYPERSPACE ") CMP #11 \ If A is not 11 (i.e. the item we've just bought is not BNE et9 \ a galactic hyperdrive), skip to et9 LDX GHYP \ Set X to the value of GHYP, which determines \ whether we have a galactic hyperdrive fitted .equip_gfrog BNE pres \ If we already have a galactic hyperdrive fitted (i.e. \ GHYP is non-zero), jump to pres to show the error \ "Galactic Hyperspace Present", beep and exit to the \ docking bay (i.e. show the Status Mode screen) DEC GHYP \ Otherwise we just splashed out on a galactic \ hyperdrive, so set GHYP to &FF (as GHYP was 0 before \ the DEC instruction) .et9 INY \ Increment Y to recursive token 117 ("MILITARY LASER") CMP #12 \ If A is not 12 (i.e. the item we've just bought is not BNE et10 \ a military laser), skip to et10 LDY new_military \ Set Y to the power level of military lasers when \ fitted to our current ship type .equip_frog BNE equip_merge \ Jump to equip_merge to install the new laser (this BNE \ is effectively a JMP as Y is never zero) .et10 INY \ Increment Y to recursive token 118 ("MINING LASER") CMP #13 \ If A is not 13 (i.e. the item we've just bought is not BNE et11 \ a mining laser), skip to et11 LDY new_mining \ Set Y to the power level of mining lasers when fitted \ to our current ship type .equip_merge \ Now to install a new laser with the laser power in Y \ and the item number in A PHA \ Store the item number in A on the stack TYA \ Store the laser power in Y on the stack PHA JSR qv \ Print a menu listing the four views, with a "View ?" \ prompt, and ask for a view number, which is returned \ in X (which now contains 0-3) PLA \ Retrieve the laser power of the new laser from the \ stack into A LDY LASER,X \ If there is no laser mounted in the chosen view (i.e. BEQ l_3113 \ LASER+X, which contains the laser power for view X, is \ zero), jump to l_3113 to fit the new laser \ We already have a laser fitted to this view, so PLA \ Retrieve the item number from the stack into A LDY #187 \ Set Y to token 27 (" LASER") so the following jump to \ pres will show the error "Laser Present", beep and \ exit to the docking bay (i.e. show the Status Mode \ screen) BNE equip_gfrog \ Jump to pres via equip_gfrog (this BNE is effectively \ a JMP as Y is never zero) .l_3113 STA LASER,X \ Fit the new laser by storing the laser power in A into \ LASER+X PLA \ Retrieve the item number from the stack into A .et11 JSR dn \ We are done buying equipment, so print the amount of \ cash left in the cash pot, then make a short, high \ beep to confirm the purchase, and delay for 1 second JMP EQSHP \ Jump back up to EQSHP to show the Equip Ship screen \ again and see if we can't track down another bargainName: EQSHP [Show more] Type: Subroutine Category: Equipment Summary: Show the Equip Ship screen (red key f3) or Buy Ship screen (CTRL-f3)Context: See this subroutine on its own page References: This subroutine is called as follows: * TT102 calls EQSHP * eq calls via err
Other entry points: err Beep, pause and go to the docking bay (i.e. show the Status Mode screen) pres Given an item number A with the item name in recursive token Y, show an error to say that the item is already present, refund the cost of the item, and then beep and exit to the docking bay (i.e. show the Status Mode screen) pres+3 Show the error to say that an item is already present, and process a refund, but do not free up a space in the hold.dn JSR TT162 \ Print a space LDA #119 \ Print recursive token 119 ("CASH:{cash} CR{crlf}") JSR spc \ followed by a space \ Fall through into dn2 to make a beep and delay for \ 1 second before returning from the subroutineName: dn [Show more] Type: Subroutine Category: Market Summary: Print the amount of money we have left in the cash pot, then make a short, high beep and delay for 1 secondContext: See this subroutine on its own page References: This subroutine is called as follows: * EQSHP calls dn * TT219 calls dn.dn2 JSR BEEP \ Call the BEEP subroutine to make a short, high beep LDY #50 \ Wait for 50/50 of a second (1 second) and return JMP DELAY \ from the subroutine using a tail callName: dn2 [Show more] Type: Subroutine Category: Text Summary: Make a short, high beep and delay for 1 second.eq JSR prx \ Call prx to set (Y X) to the price of equipment item \ number A JSR LCASH \ Subtract (Y X) cash from the cash pot, but only if \ we have enough cash BCS c \ If the C flag is set then we did have enough cash for \ the transaction, so jump to c to return from the \ subroutine (as c contains an RTS) LDA #197 \ Otherwise we don't have enough cash to buy this piece \ of equipment, so set A to the value for recursive \ token 37 ("CASH") .query_beep JSR prq \ Print the recursive token in A followed by a question \ mark JMP err \ Jump to err to beep, pause and go to the docking bay \ (i.e. show the Status Mode screen)Name: eq [Show more] Type: Subroutine Category: Equipment Summary: Subtract the price of equipment from the cash potContext: See this subroutine on its own page References: This subroutine is called as follows: * EQSHP calls eq * EQSHP calls via query_beep
If we have enough cash, subtract the price of a specified piece of equipment from our cash pot and return from the subroutine. If we don't have enough cash, exit to the docking bay (i.e. show the Status Mode screen).
Arguments: A The item number of the piece of equipment (0-11) as shown in the table at PRXS
Other entry points: query_beep Print the recursive token given in A followed by a question mark, then make a beep, pause and go to the docking bay (i.e. show the Status Mode screen)SEC \ Decrement A (for when this routine is called via SBC #1 \ prx-3) .prx ASL A \ Set A = A * 2, so it can act as an index into the \ PRXS table, which has two bytes per entry BEQ n_fcost \ If A = 0, skip the following, as we are fetching the \ price of fuel, and fuel is always the same price, \ regardless of ship type ADC new_costs \ In Elite-A the PRXS table has multiple sections, for \ the different types of ship we can buy, and the offset \ to the price table for our current ship is held in \ new_costs, so this points the index in A to the \ correct section of the PRXS table for our current ship .n_fcost TAY \ Copy A into Y, so it can be used as an index LDX PRXS,Y \ Fetch the low byte of the price into X LDA PRXS+1,Y \ Fetch the high byte of the price into A and transfer TAY \ it to X, so the price is now in (Y X) .c RTS \ Return from the subroutineName: prx [Show more] Type: Subroutine Category: Equipment Summary: Return the price of a piece of equipmentContext: See this subroutine on its own page References: This subroutine is called as follows: * eq calls prx * EQSHP calls prx * EQSHP calls via prx-3 * status_equip calls via prx-3 * eq calls via c
This routine returns the price of equipment as listed in the table at PRXS.
Arguments: A The item number of the piece of equipment (0-13) as shown in the table at PRXS
Returns: (Y X) The item price in Cr * 10 (Y = high byte, X = low byte) (A X) Contains the same as (Y X)
Other entry points: prx-3 Return the price of the item with number A - 1 c Contains an RTS.qv LDA tek \ If the current system's tech level is less than 8, CMP #8 \ skip the next two instructions, otherwise we clear the BCC P%+7 \ screen to prevent the view menu from clashing with the \ longer equipment menu available in higher tech systems LDA #32 \ Clear the top part of the screen, draw a border box, JSR TT66 \ and set the current view type in QQ11 to 32 (Equip \ Ship screen) LDY #16 \ Move the text cursor to row 16, and at the same time STY YC \ set YC to a counter going from 16 to 19 in the loop \ below .qv1 LDX #12 \ Move the text cursor to column 12 STX XC LDA YC \ Fetch the counter value from YC into A CLC \ Print ASCII character "0" - 16 + A, so as A goes from ADC #'0'-16 \ 16 to 19, this prints "0" through "3" followed by a JSR spc \ space LDA YC \ Print recursive text token 80 + YC, so as YC goes from CLC \ 16 to 19, this prints "FRONT", "REAR", "LEFT" and ADC #80 \ "RIGHT" JSR TT27 INC YC \ Move the text cursor down a row, and increment the \ counter in YC at the same time LDA new_mounts \ Set A = new_mounts + 16, so A now contains a value of ORA #16 \ 17, 18 or 20, depending on the number of laser mounts \ that our current ship supports (in other words, it's \ one more than the corresponding value in the YC \ counter, which is going from 16 to 19, not 17 to 20) CMP YC \ If the loop counter in YC hasn't yet reached the BNE qv1 \ value in A, then loop back up to qv1 to print the next \ view in the menu, so this loops us back until we have \ printed all of the laser mounts defined by the value \ of new_mounts JSR CLYNS \ Clear the bottom three text rows of the upper screen, \ and move the text cursor to the first cleared row .qv2 LDA #175 \ Print recursive text token 15 ("VIEW ") followed by JSR prq \ a question mark JSR TT217 \ Scan the keyboard until a key is pressed, and return \ the key's ASCII code in A (and X) SEC \ Subtract ASCII "0" from the key pressed, to leave the SBC #'0' \ numeric value of the key in A (if it was a number key) CMP new_mounts \ If A < new_mounts, then our current ship supports this BCC qv3 \ view number, so jump down to qv3 as we are done JSR CLYNS \ Otherwise we didn't get a valid view number, so clear \ the bottom three text rows of the upper screen, and \ move the text cursor to column 1 on row 21 JMP qv2 \ Jump back to qv2 to try again .qv3 TAX \ We have a valid view number, so transfer it to X RTS \ Return from the subroutineName: qv [Show more] Type: Subroutine Category: Equipment Summary: Print a menu of the four space views, for buying lasersContext: See this subroutine on its own page References: This subroutine is called as follows: * EQSHP calls qv
Print a menu in the bottom-middle of the screen, at row 16, column 12, that lists the four available space views, like this: 0 Front 1 Rear 2 Left 3 Right Also print a "View ?" prompt and ask for a view number. The menu is shown when we choose to buy a new laser in the Equip Ship screen.
Returns: X The chosen view number (0-3).hm JSR TT103 \ Draw small crosshairs at coordinates (QQ9, QQ10), \ which will erase the crosshairs currently there JSR TT111 \ Select the system closest to galactic coordinates \ (QQ9, QQ10) JSR TT103 \ Draw small crosshairs at coordinates (QQ9, QQ10), \ which will draw the crosshairs at our current home \ system JMP CLYNS \ Clear the bottom three text rows of the upper screen, \ and move the text cursor to the first cleared row \ Return from the subroutine using a tail callName: hm [Show more] Type: Subroutine Category: Charts Summary: Select the closest system and redraw the chart crosshairsContext: See this subroutine on its own page References: This subroutine is called as follows: * hyp calls hm * TT102 calls hm
Set the system closest to galactic coordinates (QQ9, QQ10) as the selected system, redraw the crosshairs on the chart accordingly (if they are being shown), and, if this is not a space view, clear the bottom three text rows of the screen.PRINT "ELITE D" PRINT "Assembled at ", ~CODE_D% PRINT "Ends at ", ~P% PRINT "Code size is ", ~(P% - CODE_D%) PRINT "Execute at ", ~LOAD% PRINT "Reload at ", ~LOAD_D% PRINT "S.2.ELTD ", ~CODE_D%, " ", ~P%, " ", ~LOAD%, " ", ~LOAD_D% \SAVE "3-assembled-output/2.ELTD.bin", CODE_D%, P%, LOAD%Save ELTD.bin
[X]
Subroutine BAY (category: Status)
Go to the docking bay (i.e. show the Status Mode screen)
[X]
Subroutine BEEP (category: Sound)
Make a short, high beep
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Subroutine CIRCLE2 (category: Drawing circles)
Draw a circle (for the planet or chart)
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Subroutine CLYNS (category: Drawing the screen)
Clear the bottom three text rows of the mode 4 screen by sending a clr_line command to the I/O processor
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Subroutine CTRL (category: Keyboard)
Scan the keyboard to see if CTRL is currently pressed
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Subroutine DELAY (category: Utility routines)
Wait for a specified time, in 1/50s of a second
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Subroutine DETOK (category: Text)
Print an extended recursive token from the TKN1 token table
[X]
Subroutine DIALS (Part 1 of 4) (category: Dashboard)
Update the dashboard: speed indicator
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Subroutine EQSHP (category: Equipment)
Show the Equip Ship screen (red key f3) or Buy Ship screen (CTRL-f3)
[X]
Subroutine FLFLLS (category: Drawing suns)
Reset the sun line heap
[X]
Subroutine FLKB (category: Keyboard)
Flush the keyboard buffer
[X]
Entry point FRCE in subroutine Main game loop (Part 6 of 6) (category: Main loop)
The entry point for the main game loop if we want to jump straight to a specific screen, by pretending to "press" a key, in which case A contains the internal key number of the key we want to "press"
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Subroutine GC2 (category: Maths (Arithmetic))
Calculate (Y X) = (A P) * 4
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Subroutine GCASH (category: Maths (Arithmetic))
Calculate (Y X) = P * Q * 4
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Subroutine HLOIN (category: Drawing lines)
Draw a horizontal line by sending a draw_hline command to the I/O processor
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Subroutine LCASH (category: Maths (Arithmetic))
Subtract an amount of cash from the cash pot
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Subroutine LL30 (category: Drawing lines)
Draw a one-segment line by sending a draw_line command to the I/O processor
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Subroutine LL5 (category: Maths (Arithmetic))
Calculate Q = SQRT(R Q)
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Subroutine MCASH (category: Maths (Arithmetic))
Add an amount of cash to the cash pot
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Subroutine MULTU (category: Maths (Arithmetic))
Calculate (A P) = P * Q
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Subroutine NLIN (category: Drawing lines)
Draw a horizontal line at pixel row 23 to box in a title
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Subroutine NLIN2 (category: Drawing lines)
Draw a screen-wide horizontal line at the pixel row in A
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Subroutine NLIN3 (category: Drawing lines)
Print a title and draw a horizontal line at row 19 to box it in
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Subroutine NLIN4 (category: Drawing lines)
Draw a horizontal line at pixel row 19 to box in a title
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Subroutine NWDAV4 (category: Market)
Print an "ITEM?" error, make a beep and rejoin the TT210 routine
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Subroutine PDESC (category: Universe)
Print the system's extended description or a mission 1 directive
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Subroutine PIXEL (category: Drawing pixels)
Draw a 1-pixel dot, 2-pixel dash or 4-pixel square by sending a draw_pixel command to the I/O processor
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Variable PRXS (category: Equipment)
Equipment prices
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Variable QQ23 (category: Market)
Market prices table
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Subroutine SQUA2 (category: Maths (Arithmetic))
Calculate (A P) = A * A
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Subroutine SUN (Part 1 of 4) (category: Drawing suns)
Draw the sun: Set up all the variables needed to draw the sun
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Subroutine TT103 (category: Charts)
Draw a small set of crosshairs on a chart
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Subroutine TT105 (category: Charts)
Draw crosshairs on the Short-range Chart, with clipping
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Subroutine TT11 (category: Text)
Print a 16-bit number, left-padded to n digits, and optional point
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Subroutine TT111 (category: Universe)
Set the current system to the nearest system to a point
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Subroutine TT123 (category: Charts)
Move galactic coordinates by a signed delta
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Subroutine TT128 (category: Drawing circles)
Draw a circle on a chart
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Subroutine TT14 (category: Drawing circles)
Draw a circle with crosshairs on a chart
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Subroutine TT146 (category: Universe)
Print the distance to the selected system in light years
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Subroutine TT15 (category: Drawing lines)
Draw a set of crosshairs
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Subroutine TT151 (category: Market)
Print the name, price and availability of a market item
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Subroutine TT152 (category: Market)
Print the unit ("t", "kg" or "g") for a market item
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Subroutine TT160 (category: Market)
Print "t" (for tonne) and a space
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Subroutine TT161 (category: Market)
Print "kg" (for kilograms)
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Subroutine TT162 (category: Text)
Print a space
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Subroutine TT163 (category: Market)
Print the headers for the table of market prices
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Subroutine TT16a (category: Market)
Print "g" (for grams)
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Subroutine TT20 (category: Universe)
Twist the selected system's seeds four times
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Subroutine TT210 (category: Market)
Show a list of current cargo in our hold, optionally to sell
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Subroutine TT217 (category: Keyboard)
Scan the keyboard until a key is pressed by sending a get_key command to the I/O processor
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Subroutine TT24 (category: Universe)
Calculate system data from the system seeds
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Subroutine TT26 (category: Text)
Print a character at the text cursor, with support for verified text in extended tokens
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Subroutine TT27 (category: Text)
Print a text token
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Subroutine TT60 (category: Text)
Print a text token and a paragraph break
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Subroutine TT66 (category: Drawing the screen)
Clear the screen and set the current view type
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Subroutine TT67 (category: Text)
Print a newline
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Subroutine TT68 (category: Text)
Print a text token followed by a colon
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Subroutine TT69 (category: Text)
Set Sentence Case and print a newline
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Subroutine TT70 (category: Universe)
Display "MAINLY " and jump to TT72
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Subroutine TT81 (category: Universe)
Set the selected system's seeds to those of system 0
[X]
[X]
Subroutine TTX69 (category: Text)
Print a paragraph break
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Subroutine cour_buy (category: Missions)
Show the Special Cargo screen (CTRL-f1)
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Subroutine cpl (category: Universe)
Print the selected system name
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Subroutine dn (category: Market)
Print the amount of money we have left in the cash pot, then make a short, high beep and delay for 1 second
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Subroutine dn2 (category: Text)
Make a short, high beep and delay for 1 second
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Subroutine encyclopedia (category: Encyclopedia)
Show the Encyclopedia screen
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Subroutine eq (category: Equipment)
Subtract the price of equipment from the cash pot
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Label equip_frog in subroutine EQSHP
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Label equip_gfrog in subroutine EQSHP
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Label equip_isspace in subroutine EQSHP
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Label equip_leap in subroutine EQSHP
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Label equip_merge in subroutine EQSHP
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Label equip_space in subroutine EQSHP
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Configuration variable f9
Internal key number for red key f9 (Inventory)
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Subroutine fwl (category: Status)
Print fuel and cash levels
[X]
Subroutine gnum (category: Market)
Get a number from the keyboard
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Subroutine jmp (category: Universe)
Set the current system to the selected system
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Subroutine msblob (category: Dashboard)
Display the dashboard's missile indicators in green
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Subroutine n_buyship (category: Buying ships)
Show the Buy Ship screen (CTRL-f3)
[X]
Variable new_energy in workspace UP
Our current ship's ship energy refresh rate when fitted with an energy unit
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Variable new_military in workspace UP
The power level of military lasers when fitted to our current ship type
[X]
Variable new_mining in workspace UP
The power level of mining lasers when fitted to our current ship type
[X]
Variable new_missiles in workspace UP
The maximum number of missiles that can be fitted to our current ship
[X]
Variable new_mounts in workspace UP
The available laser mounts in our current ship
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Label not_cyclop in subroutine TT25
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Subroutine pr2 (category: Text)
Print an 8-bit number, left-padded to 3 digits, and optional point
[X]
Subroutine pr5 (category: Text)
Print a 16-bit number, left-padded to 5 digits, and optional point
[X]
Subroutine pr6 (category: Text)
Print 16-bit number, left-padded to 5 digits, no point
[X]
Subroutine prq (category: Text)
Print a text token followed by a question mark
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Subroutine prx (category: Equipment)
Return the price of a piece of equipment
[X]
Entry point query_beep in subroutine eq (category: Equipment)
Print the recursive token given in A followed by a question mark, then make a beep, pause and go to the docking bay (i.e. show the Status Mode screen)
[X]
Subroutine qv (category: Equipment)
Print a menu of the four space views, for buying lasers
[X]
Entry point sell_equip in subroutine STATUS (category: Status)
Show the Sell Equipment screen, i.e. show a "Sell(Y/N)?" prompt as we print each item of equipment
[X]
Label sell_escape in subroutine sell_jump
[X]
Subroutine sell_jump (category: Equipment)
Show the Sell Equipment screen (CTRL-f2)
[X]
Subroutine sell_yn (category: Text)
Print a "Sell(Y/N)?" prompt and get a number from the keyboard
[X]
Subroutine spc (category: Text)
Print a text token followed by a space
[X]
Subroutine status_equip (category: Text)
Print equipment name, adding a sell prompt if appropriate
[X]
Subroutine tnpr (category: Market)
Work out if we have space for a specific amount of cargo
[X]
Subroutine tube_write (category: Tube)
As the parasite, send a byte across the Tube to the I/O processor
[X]
Subroutine update_pod (category: Dashboard)
Ensure the correct palette is shown for the dashboard/hyperspace tunnel, by sending a write_pod command to the I/O processor
[X]
Subroutine var (category: Market)
Calculate QQ19+3 = economy * |economic_factor|