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Add defines for track/sector sizes

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Peter Evans 2018-02-03 00:24:22 -06:00
parent 5ac2fbdbee
commit 5fc0206ff6
1 changed files with 49 additions and 1 deletions
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50
include/apple2.enc.h
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@ -9,7 +9,55 @@
* with using other values for it, and this one in particular is used in
* WinApple, so I went with it.
*/
#define ENC_VOLUME 0xfe
#define ENC_VOLUME 0xfe
/*
* The number of tracks that a DOS 3.3 disk would have.
*/
#define ENC_NUM_TRACKS 35
/*
* The number of sectors within a single track of data for a DOS 3.3
* disk.
*/
#define ENC_NUM_SECTORS 16
/*
* A decoded sector is 256 bytes long
*/
#define ENC_DSECTOR 0x100
/*
* And a track--being composed of 16 sectors--is 4096 bytes long, or 4k
* bytes. (256 * 16 = 4096)
*/
#define ENC_DTRACK 0x1000
/*
* An encoded sector is 382 bytes long, and is comprised of a sector
* header plus padding bytes both before _and_ after the data field.
*/
#define ENC_ESECTOR 0x17e
/*
* An encoded track contains 16 sectors, as mentioned for ENC_DTRACK.
* But it also contains some additional padding (48 bytes-worth).
*/
#define ENC_ETRACK 0x1810
/*
* A sector header consists of some byte markers--all byte markers in
* 6-and-2 encoding are 3 bytes long--and also some metadata, such as
* the track number, the sector number, the volume, and an XOR'd
* combination of all three.
*/
#define ENC_ESECTOR_HEADER 0xe
/*
* The track header (as mentioned for ENC_ETRACK) is 48 bytes of--well,
* nothing really, just padding.
*/
#define ENC_ETRACK_HEADER 0x30
extern int apple2_enc_4n4(vm_segment *, int, vm_8bit);
extern int apple2_enc_sector(vm_segment *, vm_segment *, int, int);