passport/src/id/rdos.a

;-------------------------------
; IDRDOS16
; identify RDOS 16-sector bootloader
;
; in:  $0800..$08FF contains T00,S00
;      first page of track buffer also contains T00,S00
; out: C clear if RDOS 16-sector bootloader found
;      C set otherwise
;      all registers clobbered
;      all other flags clobbered
;-------------------------------
!macro IDRDOS16 {
         lda   #$00
         tax
         ldy   #$0E
         jsr   compare    ; if T00,S00,$00 ==
         !byte $01
         !byte $A9,$60    ; LDA #$60
         !byte $8D,$01,$08; STA $0801
         !byte $A2,$00    ; LDX #$00
         !byte $A0,$1F    ; LDY #$1F
         !byte $B9,$00,$08; LDA $0800,Y
         !byte $49        ; EOR
                          ; passport-test-suite/Roadwar 2000.woz [C=0] matches
}