passport/src/patchers/t00_bademu.a
2021-06-21 10:33:16 -04:00

35 lines
1.1 KiB
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Executable File

;-------------------------------
; #BADEMU
; RWTS checks for timing bit by
; checking if data latch is still
; $D5 after waiting "too long"
; but this confuses legacy emulators
; (AppleWin, older versions of MAME)
; so we patch it for compatibility
;
; variant 1:
; - Dino Dig (Troll Associates)
; - Make A Face (Troll Associates)
; - Let's Go There: Beginning Map and Geography Skills (Troll Associates)
;
; variant 2:
; - Dinosaur Days (Pelican Software)
;-------------------------------
T00_BADEMU
; gTrack = 0
; Caller found DOS 3.3 RWTS
ldy #$05
jsr SearchTrack
!byte $BD,$8C,$C0; LDA $C08C,X
!byte $C9,$D5 ; CMP #$D5
bcs + ; passport-test-suite/Beginning Map and Geography Skills.woz [C=0] matches
; passport-test-suite/Dinosaur Days.woz [C=0] matches at a different offset
jsr PrintByID
!byte s_d5timing
inx
inx
jsr modify1 ; then change $C0 to $BF to avoid hitting softswitch
!byte $BF
+