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70 lines
1.8 KiB
C
70 lines
1.8 KiB
C
#ifndef _APPLE2_ENC_H_
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#define _APPLE2_ENC_H_
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#include "vm_bits.h"
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#include "vm_segment.h"
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/*
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* This is a magic number for the disk volume; I haven't experimented
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* with using other values for it, and this one in particular is used in
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* WinApple, so I went with it.
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*/
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#define ENC_VOLUME 0xfe
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/*
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* The number of tracks that a DOS 3.3 disk would have.
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*/
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#define ENC_NUM_TRACKS 35
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/*
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* The number of sectors within a single track of data for a DOS 3.3
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* disk.
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*/
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#define ENC_NUM_SECTORS 16
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/*
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* A decoded sector is 256 bytes long
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*/
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#define ENC_DSECTOR 0x100
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/*
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* And a track--being composed of 16 sectors--is 4096 bytes long, or 4k
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* bytes. (256 * 16 = 4096)
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*/
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#define ENC_DTRACK 0x1000
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/*
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* An encoded sector is 396 bytes long, and is comprised of a sector
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* header plus padding bytes both before _and_ after the data field.
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*/
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#define ENC_ESECTOR 0x1a0
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/*
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* An encoded track contains 16 sectors, as mentioned for ENC_DTRACK.
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* But it also contains some additional padding (48 bytes-worth).
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*/
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#define ENC_ETRACK 0x1a00
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/*
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* A sector header consists of some byte markers--all byte markers in
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* 6-and-2 encoding are 3 bytes long--and also some metadata, such as
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* the track number, the sector number, the volume, and an XOR'd
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* combination of all three.
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*/
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#define ENC_ESECTOR_HEADER 0x13
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/*
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* The track header (as mentioned for ENC_ETRACK) is 48 bytes of--well,
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* nothing really, just padding.
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*/
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#define ENC_ETRACK_HEADER 0x30
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extern int apple2_enc_4n4(vm_segment *, int, vm_8bit);
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extern int apple2_enc_sector(vm_segment *, vm_segment *, int, int);
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extern int apple2_enc_sector_header(vm_segment *, int, int, int);
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extern int apple2_enc_track(int, vm_segment *, vm_segment *, int, int);
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extern vm_segment *apple2_enc_dos(int, vm_segment *);
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extern vm_segment *apple2_enc_nib(vm_segment *);
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#endif
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