passport/src/id/pascal.a

;-------------------------------
; IDPascal
; identify Apple Pascal bootloader
;
; in:    $0800..$08FF contains T00,S00
;        first page of track buffer also contains T00,S00
; out:   C clear if Apple Pascal bootloader found
;        C set otherwise
;        A = 0
;        X = 0
;        all other registers & flags clobbered
;-------------------------------
!macro IDPascal {
;
; Apple Pascal signature (version < 1.3)
; 7th position not included, to catch alternate jump
; addresses (e.g. Wizardry I, Sundog Frozen Legacy)
; 8th position not included, to catch PFS
;
         lda   #$00
         tax
         ldy   #$06
         jsr   compare    ; if T00,S00,$00 ==
         !byte $01
         !byte $E0,$60
         !byte $F0,$03
         !byte $4C
         bcc   @notPascal ; passport-test-suite/Wizplus.woz [C=0] matches
                          ; passport-test-suite/PFS A02.woz [C=0] matches
;
; Apple Pascal 1.3 signature [thanks Marco V.]
;
                         ; passport-test-suite/Triangles Through Octagons.woz [C=1] reaches here
         jsr   compare    ; or if T00,S00,$00 ==
         !byte $01
         !byte $E0,$70
         !byte $B0,$04
         !byte $E0
@notPascal                ; passport-test-suite/Triangles Through Octagons.woz [C=0] matches
}