Equipment: EQSHP

       Name: EQSHP                                                   [Show more]
       Type: Subroutine
   Category: Equipment
    Summary: Show the Equip Ship screen
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * refund calls EQSHP
             * TT102 calls EQSHP
             * UpdateEquipment calls via equi1


 Other entry points:

   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)

   equi1                A re-entry point into the key-pressing loop, used when
                        processing key presses in subroutines


.EQSHP

 LDA #$B9               ; Clear the screen and set the view type in QQ11 to $B9
 JSR SetNewViewType     ; (Equip Ship)

 LDX languageIndex      ; Move the text cursor to the correct column for the
 LDA xEquipShip,X       ; Equip Ship title in the chosen language
 STA XC

 LDA #207               ; Print recursive token 47 ("EQUIP") on the top row
 JSR NLIN3

 LDA #%10000000         ; Set bit 7 of QQ17 to switch to Sentence Case, with the
 STA QQ17               ; next letter in capitals

 LDA tek                ; Fetch the tech level of the current system from tek
 CLC                    ; and add 3 (the tech level is stored as 0-14, so A is
 ADC #3                 ; now set to between 3 and 17)

 CMP #12                ; If A >= 12 then set A = 14, so A is now set to between
 BCC P%+4               ; 3 and 14
 LDA #14

 STA Q                  ; Set QQ25 = A (so QQ25 is in the range 3-14 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 4-15 and contains
                        ; QQ25 + 1, i.e. the highest item number on sale + 1)

 LDA #70                ; Set A = 70 - QQ14, where QQ14 contains the current
 SEC                    ; fuel in light years * 10, so this leaves the amount
 SBC QQ14               ; of fuel we need to fill 'er up (in light years * 10)

 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

 JSR PrintEquipment+2   ; Print the name and price for the equipment item in X

 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

 LDX #1                 ; Set XX13 = 1 to pass to the HighlightEquipment routine
 STX XX13               ; so we highlight the first item on the list (Fuel)

 JSR HighlightEquipment ; Highlight the item of equipment in XX13, i.e. Fuel

 JSR dn                 ; Print the amount of money we have left in the cash pot

 JSR SetScreenForUpdate ; Get the screen ready for updating by hiding all
                        ; sprites, after fading the screen to black if we are
                        ; changing view

 JSR DrawCobraMkIII     ; Draw the Cobra Mk III that we embellish with our
                        ; fitted equipment

 JSR UpdateView         ; Update the view

                        ; The Equip Ship view is now on-screen, so we move on to
                        ; checking for key presses

.equi1

 SETUP_PPU_FOR_ICON_BAR ; If the PPU has started drawing the icon bar, configure
                        ; the PPU to use nametable 0 and pattern table 0

 LDA controller1Up      ; If the up button has not been pressed, jump to equi2
 BPL equi2              ; to keep checking for other buttons

 JMP MoveEquipmentUp    ; Move the currently selected item up the list of
                        ; equipment and rejoin the loop by jumping up to equi1
                        ; to keep checking for other buttons

.equi2

 LDA controller1Down    ; If the down button has not been pressed, jump to equi3
 BPL equi3              ; to keep checking for other buttons

 JMP MoveEquipmentDown  ; Move the currently selected item down the list of
                        ; equipment and rejoin the loop by jumping up to equi1
                        ; to keep checking for other buttons

.equi3

 LDA controller1A       ; If the A button has been pressed, jump to equi4 to
 BMI equi4              ; process a purchase

 LDA iconBarChoice      ; If iconBarChoice = 0 then nothing has been chosen on
 BEQ equi1              ; the icon bar (if it had, iconBarChoice would contain
                        ; the number of the chosen icon bar button), so loop
                        ; back to equi1 to keep checking for button presses

                        ; If we get here then either a choice has been made on
                        ; the icon bar during NMI and the number of the icon bar
                        ; button is in iconBarChoice, or the Start button has
                        ; been pressed to pause the game and iconBarChoice is 80

 JSR CheckForPause      ; If the Start button has been pressed then process the
                        ; pause menu and set the C flag, otherwise clear it

 BCS equi1              ; If it was the pause button, loop back to equi1 to pick
                        ; up where we left off and keep checking for button
                        ; presses

 RTS                    ; Otherwise a choice has been made from the icon bar, so
                        ; return from the subroutine

.equi4

 JSR UpdateSaveCount    ; Update the save counter for the current commander

 LDA XX13               ; Set A = XX13 - 1, so A contains the item number of the
 SEC                    ; currently selected item, less 1, which will be the
 SBC #1                 ; actual number of the item we want to buy

 PHA                    ; Store the value of A on the stack, so we can retrieve
                        ; it after the call to eq

 JSR eq                 ; Call eq to subtract the price of the item we want to
                        ; buy (which is in A) from our cash pot

 BCS equi5              ; If we had enough cash to make the purchase, then the C
                        ; flag will be set by eq, so jump to equi5 with the
                        ; original value of A still on the stack

                        ; If we get here then we didn't have enough cash to make
                        ; the purchase

 PLA                    ; Retrieve the value of A from the stack, so A contains
                        ; the number of the item we couldn't afford

 JSR DrawScreenInNMI    ; Configure the NMI handler to draw the screen, so the
                        ; screen gets updated

 JMP equi1              ; Loop back up to equi1 to keep checking for button
                        ; presses

.equi5

                        ; If we get here then we just successfully bought an
                        ; item of equipment

 PLA                    ; Retrieve the value of A from the stack, so A contains
                        ; the number of the item we just bought

 BNE et0                ; If A is not 0 (i.e. the item we've just bought is not
                        ; fuel), skip to et0

 PHA                    ; Store the value of A on the stack, so we can retrieve
                        ; it after the following calculation

 LDA QQ14               ; Fetch our current fuel level from Q114 into A

 CLC                    ; Increment our fuel level in A
 ADC #1

 CMP #71                ; If A < 71 then the tank is not overflowing, so jump to
 BCC equi6              ; equi6 to store the updated fuel level

 LDY #105               ; Set Y to recursive token 105 ("FUEL") to display as
                        ; the error in the call to pres

 PLA                    ; Restore A from the stack

 JMP pres               ; Jump to pres to show the error "Fuel Present", beep
                        ; and exit to the docking bay (i.e. show the Status Mode
                        ; screen)

.equi6

 STA QQ14               ; Update the fuel level in QQ14 to the value in A, as we
                        ; have just bought some fuel

 PLA                    ; Restore A from the stack, so it once again contains
                        ; the number of the item we are buying

.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 #5                 ; If buying this missile would give us 5 missiles, this
 BCS pres               ; is more than the maximum of 4 missiles that we can
                        ; fit, so jump to pres to show the error "All Present",
                        ; beep and exit to the docking bay (i.e. show the Status
                        ; Mode screen)

 STX NOMSL              ; Otherwise update the number of missiles in NOMSL

 LDA #1                 ; Set A to 1 as the call to msblob 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

.et1

 LDY #107               ; Set Y to recursive token 107 ("LARGE CARGO{sentence
                        ; case} BAY")

 CMP #2                 ; If A is not 2 (i.e. the item we've just bought is not
 BNE et2                ; a large cargo bay), skip to et2

 LDX #37                ; If our current cargo capacity in CRGO is 37, then we
 CPX CRGO               ; already have a large cargo bay fitted, so jump to pres
 BEQ pres               ; to show the error "Large Cargo Bay Present", beep and
                        ; exit to the docking bay (i.e. show the Status Mode
                        ; screen)

 STX CRGO               ; Otherwise we just scored ourselves a large cargo bay,
                        ; so update our current cargo capacity in CRGO to 37

.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

 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)

 LDA #POW+9             ; Call refund with A set to the power of the new pulse
 JMP refund             ; laser to install the new laser and process a refund if
                        ; we already have a laser fitted to this view
                        ;
                        ; The refund routine jumps back to EQSHP, so this also
                        ; redisplays the Equip Ship screen

 LDA #4                 ; Set A to 4 as we just overwrote the original value,
                        ; and we still need it set correctly so we can continue
                        ; through the conditional statements for all the other
                        ; equipment

.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

 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)

 LDA #POW+128           ; Call refund with A set to the power of the new beam
 JMP refund             ; laser to install the new laser and process a refund if
                        ; we already have a laser fitted to this view
                        ;
                        ; The refund routine jumps back to EQSHP, so this also
                        ; redisplays the Equip Ship screen

.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

 STY K                  ; Store the item's name in K

 PHA                    ; Wait until the next NMI interrupt has passed (i.e. the
 JSR WaitForNMI         ; next VBlank), preserving the value in A via the stack
 PLA

 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 #2                 ; Move the text cursor to column 2 on row 17
 STA XC
 LDA #17
 STA YC

 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_b2

.equi7

 JSR TT162              ; Print a space

 LDA XC                 ; If the text cursor is not in column 31, loop back to
 CMP #31                ; equi7 to keep printing spaces until it reaches column
 BNE equi7              ; 31 at the right end of the screen, so we clear up to
                        ; the end of the line containing the error message

 JSR BOOP               ; Call the BOOP routine to make a low, long beep to
                        ; indicate an error

 JSR DrawScreenInNMI    ; Configure the NMI handler to draw the screen, so the
                        ; screen gets updated

 LDY #40                ; Wait until 40 NMI interrupts have passed (i.e. the
 JSR DELAY              ; next 40 VBlanks)

 LDA #6                 ; Move the text cursor to column 6
 STA XC

 LDA #17                ; Move the text cursor to row 17
 STA YC

.equi8

 JSR TT162              ; Print a space

 LDA XC                 ; If the text cursor is not in column 31, loop back to
 CMP #31                ; equi8 to keep printing spaces until it reaches column
 BNE equi8              ; 31 at the right end of the screen, so we clear the
                        ; whole line containing the error message

 JSR dn                 ; Print the amount of money we have left in the cash pot

 JSR DrawEquipment_b6   ; Draw the currently fitted equipment onto the Cobra Mk
                        ; III image

 JSR DrawScreenInNMI    ; Configure the NMI handler to draw the screen, so the
                        ; screen gets updated

 JMP equi1              ; Loop back up to equi1 to keep checking for button
                        ; presses

.equi9

 JMP pres               ; Jump to pres to show an error, beep and exit to the
                        ; docking bay (i.e. show the Status Mode screen)

 JSR DrawScreenInNMI    ; Configure the NMI handler to draw the screen, so the
                        ; screen gets updated

 JMP equi1              ; Loop back up to equi1 to keep checking for button
                        ; presses

.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)

.et7

 INY                    ; Increment Y to recursive token 113 ("ENERGY BOMB")

 CMP #8                 ; If A is not 8 (i.e. the item we've just bought is not
 BNE et8                ; an energy bomb), skip to et8

 LDX BOMB               ; If we already have an energy bomb fitted (i.e. BOMB
 BNE pres               ; is non-zero), jump to pres to show the error "Energy
                        ; Bomb Present", beep and exit to the docking bay (i.e.
                        ; show the Status Mode screen)

 LDX #$7F               ; Otherwise we just bought an energy bomb, so set BOMB
 STX BOMB               ; to $7F

.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 equi9              ; non-zero), jump to pres via equi9 to show the error
                        ; "Energy Unit Present", beep and exit to the docking
                        ; bay (i.e. show the Status Mode screen)

 INC ENGY               ; Otherwise we just picked up an energy unit, so set
                        ; ENGY to 1 (as ENGY was 0 before the INC instruction)

.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 equi9              ; DKCMP is non-zero), jump to pres via equi9 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               ; If we already have a galactic hyperdrive fitted (i.e.
 BNE equi9              ; GHYP is non-zero), jump to pres via equi9 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

 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)

 LDA #Armlas            ; Call refund with A set to the power of the new
 JMP refund             ; military laser to install the new laser and process a
                        ; refund if we already have a laser fitted to this view
                        ;
                        ; The refund routine jumps back to EQSHP, so this also
                        ; redisplays the Equip Ship screen

.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

 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)

 LDA #Mlas              ; Call refund with A set to the power of the new mining
 JMP refund             ; laser to install the new laser and process a refund if
                        ; we already have a laser fitted to this view
                        ;
                        ; The refund routine jumps back to EQSHP, so this also
                        ; redisplays the Equip Ship screen

.et11

 JSR equi10             ; Call equi10 below to print the amount of money we have
                        ; left and make a short, high beep to indicate that the
                        ; transaction was successful

 JMP UpdateEquipment    ; Jump up to UpdateEquipment to highlight the newly
                        ; bought item of equipment, update the Cobra Mk III,
                        ; redraw the screen and rejoin the main EQSHP routine to
                        ; continue checking for button presses

.equi10

 SETUP_PPU_FOR_ICON_BAR ; If the PPU has started drawing the icon bar, configure
                        ; the PPU to use nametable 0 and pattern table 0

 JSR dn                 ; Print the amount of money we have left in the cash pot

 JMP BEEP_b7            ; Call the BEEP subroutine to make a short, high beep
                        ; and return from the subroutine using a tail call