53 lines
1.0 KiB
ArmAsm
53 lines
1.0 KiB
ArmAsm
;
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; Oliver Schmidt, 24.03.2005
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;
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; dhandle_t __fastcall__ dio_open (unsigned char device);
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;
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.export _dio_open
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.import return0, __dos_type, isdevice
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.include "errno.inc"
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.include "mli.inc"
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.include "zeropage.inc"
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_dio_open:
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; Check for ProDOS 8
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ldx __dos_type
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bne :+
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lda #$01 ; "Bad system call number"
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bne oserr ; Branch always
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; Convert from 00DDDSSS format to DSSS00DD format
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: tax
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clc
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asl
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asl
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asl
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asl
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sta tmp1
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txa
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lsr
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lsr
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lsr
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lsr
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ora tmp1
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; Check for valid device
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tax
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jsr isdevice
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beq :+
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lda #$28 ; "No device connected"
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; Return oserror
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oserr: sta __oserror
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jmp return0
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; Return success
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: txa
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ldx #$00
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stx __oserror
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rts
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