mirror of
https://github.com/erkyrath/infocom-zcode-terps.git
synced 2026-04-26 04:17:04 +00:00
95 lines
2.5 KiB
NASM
95 lines
2.5 KiB
NASM
TITLE "Apple ][ YZIP (c)Infocom","--- START OF APPLE ][ INTERPRETER ---"
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ORG INTR_BEGIN
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;
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; Set up for Double HiRes full screen graphics
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;
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sta PAGE2SW+OFF ; turn off page 2
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sta TEXTSW+OFF ; turn off text - turn on graphics
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sta HIRESSW+ON ; turn on high resolution
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sta MIXEDSW+OFF ; full screen graphics
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sta COL80SW+ON ; turn on 80 column
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sta IOUDIS+OFF ; turn ON (it too is backwards) Dhires switch
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sta DHIRESW+OFF ; turn ON (it's backwards!) Dhires
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sta STORE80+ON ; turn on aux page display ability
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lda BNK2SET ; read/write RAM, bank 2
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lda BNK2SET
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;
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; copy in progame from boot code
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;
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ldx #0 ; start at first letter
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MVPRE:
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lda BORG+3,X ; get letter
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beq MVPREX ; all done
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sta GAME1NAME,X ; save letter
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sta GAME2NAME,X ; save letter
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sta GAME,X ; save for asking about later
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inx ; next letter
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bne MVPRE ; do gen
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MVPREX:
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stx GAMEL ; save length of game name
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lda #'.' ; get extension for names
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sta GAME1NAME,X ; save letter
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sta GAME2NAME,X ; save letter
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inx ; next letter
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lda #'D' ; for data segments
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sta GAME1NAME,X ; save letter
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sta GAME2NAME,X ; save letter
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inx ; points to number
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inx ; inclusive count for length
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stx GAME1NML ; save length of name
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stx GAME2NML ; save length of name
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lda #VERSID ; put in version number
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sta ZBEGIN+ZINTWD+1
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inc ZSP+LO ; INIT Z-STACK POINTERS
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inc OLDZSP+LO ; TO "1"
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inc SCREENF ; TURN DISPLAY ON
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inc SCRIPT ; enable scripting
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lda WINTABLE+LO ; set WINDOW to point to window 0
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sta WINDOW+LO
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lda WINTABLE+HI
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sta WINDOW+HI ; okay, it does
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lda ARG1+LO ; using mouse?
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beq ZBEGIN1 ; nope
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ora #$78 ; point to correct screen holes
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sta MSFIX0+1
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sta MSFIX1+1 ; and modify code to point to correct spot
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sta MSFIX2+1
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lda ARG1+LO
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ora #$F8 ; and one more
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sta MSFIX2+1
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ZBEGIN1:
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lda #$FF ; do a clear -1 to start off
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sta ARG1+LO ; so arg 1 is this
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jsr ZCLR ; doing it
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GET_PREFIX GPRE_PB ; get where we are to start
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lda D3SEG+HI ; start DSEGS at .D2
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sta DSEGS+HI
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lda D3SEG+LO
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sta DSEGS+LO
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lda #1 ; open game file .D2 please
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jsr FETCH_FILE ; we did that
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lda INFODOS ; are we on little dos?
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beq ZBEGIN2 ; nope
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jsr GET_SPECIAL ; do special preloading if so
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ZBEGIN2:
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lda #2 ; and just for giggles, do the
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jsr FETCH_FILE ; same for game file .D3
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jsr VLDZPC ; MAKE ZPC VALID
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jsr NEXTPC ; skip over # of locals
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; ... AND FALL INTO MAIN LOOP
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END
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