Skip to navigation

⌂ ∞ ▽ Elite on the 6502

Market: TT210

[NES version, Bank 0]

       Name: TT210                                                   [Show more]
       Type: Subroutine
   Category: Market
    Summary: Show a list of current cargo in our hold, optionally to sell

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * TT213 calls TT210




 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



.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

 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

 STY QQ29               ; Store the current item number in QQ29

 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_b2

 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)

.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)

 JSR TT69               ; Call TT69 to set Sentence Case and print a newline

 LDA TRIBBLE            ; If there are any Trumbles in the hold, skip the
 ORA TRIBBLE+1          ; following RTS and continue on (in the Master version,
 BNE P%+5               ; there are never any Trumbles, so this value will
                        ; always be zero)

.zebra

 JMP UpdateViewWithFade ; There are no Trumbles in the hold, so update the view,
                        ; fading the screen to black first if required, and
                        ; return from the subroutine using a tail call

                        ; If we get here then we have Trumbles in the hold, so
                        ; we print out the number of Trumbles and a random
                        ; adjective

 CLC                    ; Clear the C flag, so the call to TT11 below doesn't
                        ; include a decimal point

 LDA #0                 ; Set A = 0, for the call to TT11 below, so we don't pad
                        ; out the number of Trumbles

 LDX TRIBBLE            ; Fetch the number of Trumbles into (Y X)
 LDY TRIBBLE+1

 JSR TT11               ; Call TT11 to print the number of Trumbles in (Y X),
                        ; with no decimal point

 LDA languageNumber     ; If bit 2 of languageNumber is set then the chosen
 AND #%00000100         ; language is French, so jump to carg1 to skip printing
 BNE carg1              ; the Trumble adjectives

 JSR DORND              ; Print out a random extended token from 111 to 114,
 AND #3                 ; (" CUDDLY", " CUTE", " FURRY" or " FRIENDLY")
 CLC
 ADC #111
 JSR DETOK_b2

 LDA languageNumber     ; If bit 1 of languageNumber is clear then the chosen
 AND #%00000010         ; language is not German, so jump to carg1 to skip the
 BEQ carg1              ; following

 LDA TRIBBLE            ; If the number of Trumbles in TRIBBLE(1 0) is more than
 AND #%11111110         ; one, jump to carg1 to skip the following
 ORA TRIBBLE+1
 BEQ carg1

 LDA #'e'               ; Print an 'e' to pluralise the adjective in German
 JSR DASC_b2

.carg1

 LDA #198               ; Print extended token 198 (" LITTLE {single
 JSR DETOK_b2           ; cap}SQUEAKY"

 LDA TRIBBLE+1          ; If we have more than 256 Trumbles, skip to DOANS
 BNE DOANS

 LDX TRIBBLE            ; If we have exactly one Trumble, jump up to zebra
 DEX
 BEQ zebra

.DOANS

 LDA #'s'               ; We have more than one Trumble, so print an 's' and
 JSR DASC_b2            ; jump up to zebra
 JMP zebra