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44 lines
1.2 KiB
Plaintext
44 lines
1.2 KiB
Plaintext
;-------------------------------
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; IDDOS32LO
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; detect earlier variant of hybrid bootloader that loads into
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; low memory ($3600) then relocates to the top of main memory
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; after loading DOS
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; in: $0800..$08FF contains T00,S00
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; first page of track buffer also contains T00,S00
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; A = 0
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; X = 0
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; out: C clear if low DOS 3.2/3.3 bootloader found
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; C set otherwise
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; A = 0
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; X = 0
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; all other registers & flags clobbered
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;-------------------------------
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!macro IDDOS32LO {
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ldy #$0F
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jsr compare
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!byte $01
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!byte $A2,$00 ; LDX #$00
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!byte $BD,$00,$08; LDA $0800,X
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!byte $9D,$00,$02; STA $0200,X
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!byte $E8 ; INX
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!byte $D0,$F7 ; BNE -
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!byte $4C,$0F,$02; JMP $020F
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bcs +
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ldx #$2F
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ldy #$08
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jsr compare
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!byte $A6,$2B ; LDX $2B
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!byte $20,$5D,$02; JSR $025D
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!byte $20,$D1,$02; JSR $02D1
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bcs +
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ldx #$41
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jsr compare3
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!byte $4C,$01,$03; JMP $0301
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bcc +
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ldx #$37
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jsr compare3
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!byte $4C,$01,$03; JMP $0301
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+ tax
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}
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