pi1541/src/gcr.h

163 lines
5.6 KiB
C

/*
gcr.h - Group Code Recording helper functions
(C) 2001-05 Markus Brenner <markus(at)brenner(dot)de>
and Pete Rittwage <peter(at)rittwage(dot)com>
based on code by Andreas Boose
V 0.33 improved sector extraction, added find_track_cycle() function
V 0.34 added MAX_SYNC_OFFSET constant, approximated to 800 GCR bytes
V 0.35 modified find_track_cycle() interface
V 0.36 added bad GCR code detection
V 0.36a added find_sector_gap(), find_sector0(), extract_GCR_track()
V 0.36d Untold number of additions and consequent bugfixes. (pjr)
*/
#ifndef _GCR_
#define _GCR_
#include "integer.h" /* Basic integer types */
//#define BYTE unsigned char
//#define DWORD unsigned int
#define MAX_TRACKS_1541 42
#define MAX_TRACKS_1571 (MAX_TRACKS_1541 * 2)
#define MAX_HALFTRACKS_1541 (MAX_TRACKS_1541 * 2)
#define MAX_HALFTRACKS_1571 (MAX_TRACKS_1571 * 2)
/* D64 constants */
#define BLOCKSONDISK 683
#define BLOCKSEXTRA 85
#define MAXBLOCKSONDISK (BLOCKSONDISK+BLOCKSEXTRA)
#define MAX_TRACK_D64 40
/* G64 constants (only needed for current VICE support */
#define G64_TRACK_MAXLEN 7928
#define G64_TRACK_LENGTH (G64_TRACK_MAXLEN+2)
/* NIB format constants */
#define NIB_TRACK_LENGTH 0x2000
#define NIB_HEADER_SIZE 0xFF
/*
number of GCR bytes until NO SYNC error
timer counts down from $d000 to $8000 (20480 cycles)
until timeout when waiting for a SYNC signal
This is approx. 20.48 ms, which is approx 1/10th disk revolution
8000 GCR bytes / 10 = 800 bytes
*/
//#define MAX_SYNC_OFFSET 800
/* this was too small for Lode Runner original (805), so increase to 820 */
//#define MAX_SYNC_OFFSET 820
#define MAX_SYNC_OFFSET 0x1500
#define SIGNIFICANT_GAPLEN_DIFF 0x20
#define GCR_BLOCK_HEADER_LEN 24
#define GCR_BLOCK_DATA_LEN 337
#define GCR_BLOCK_LEN (GCR_BLOCK_HEADER_LEN + GCR_BLOCK_DATA_LEN)
/* To calculate the bytes per rotation:
4,000,000 * 60
b/minute = ------------------------------------------------ = x bytes/minute
speed_zone_divisor * 8bits
4,000,000 is the base clock frequency divided by 4.
8 is the number of bits per byte.
60 gets us to a minute of data, which we can then divide by RPM to
get our numbers.
speed zone divisors are 13, 14, 15, 16 for densities 3, 2, 1, 0 respectively
*/
#define DENSITY3 2307692.308 // bytes per minute
#define DENSITY2 2142857.143
#define DENSITY1 2000000.000
#define DENSITY0 1875000.000
/* Some disks have much less data than we normally expect to be able to write at a given density.
It's like short tracks, but it's a mastering issue not a protection.
This keeps us from getting errors in the track cycle detection */
#define CAP_MIN_ALLOWANCE 150
/* minimum amount of good sequential GCR for formatted track */
#define GCR_MIN_FORMATTED 64 // chessmaster track 29 is shortest so far
/* Disk Controller error codes */
#define SECTOR_OK 0x01
#define HEADER_NOT_FOUND 0x02
#define SYNC_NOT_FOUND 0x03
#define DATA_NOT_FOUND 0x04
#define BAD_DATA_CHECKSUM 0x05
#define BAD_GCR_CODE 0x06
#define VERIFY_ERROR 0x07
#define WRITE_PROTECTED 0x08
#define BAD_HEADER_CHECKSUM 0x09
#define ID_MISMATCH 0x0b
#define DISK_NOT_INSERTED 0x0f
#define BM_MATCH 0x10
#define BM_NO_CYCLE 0x20
#define BM_NO_SYNC 0x40
#define BM_FF_TRACK 0x80
#define ALIGN_NONE 0
#define ALIGN_GAP 1
#define ALIGN_SEC0 2
#define ALIGN_LONGSYNC 3
#define ALIGN_WEAK 4
#define ALIGN_VMAX 5
#define ALIGN_AUTOGAP 6
#define GCR_MASK_BAD_FIRST 0
#define GCR_MASK_BAD_LAST 1
/* global variables */
extern char sector_map_1541[];
extern BYTE speed_map_1541[];
extern int capacity[];
extern int capacity_min[];
extern int capacity_max[];\
extern int gap_match_length;
/* prototypes */
int find_sync(BYTE ** gcr_pptr, BYTE * gcr_end);
void convert_4bytes_to_GCR(BYTE * buffer, BYTE * ptr);
int convert_4bytes_from_GCR(BYTE * gcr, BYTE * plain);
int extract_id(BYTE * gcr_track, BYTE * id);
int extract_cosmetic_id(BYTE * gcr_track, BYTE * id);
size_t find_track_cycle(BYTE ** cycle_start, BYTE ** cycle_stop, int cap_min,
int cap_max);
size_t find_nondos_track_cycle(BYTE ** cycle_start, BYTE ** cycle_stop,
int cap_min, int cap_max);
BYTE convert_GCR_sector(BYTE * gcr_start, BYTE * gcr_end,
BYTE * d64_sector, int track, int sector, BYTE * id);
void convert_sector_to_GCR(BYTE * buffer, BYTE * ptr,
int track, int sector, BYTE * diskID, int error);
BYTE * find_sector_gap(BYTE * work_buffer, int tracklen, size_t * p_sectorlen);
BYTE * find_sector0(BYTE * work_buffer, int tracklen, size_t * p_sectorlen);
int extract_GCR_track(BYTE * destination, BYTE * source, int * align,
int force_align, size_t cap_min, size_t cap_max);
int replace_bytes(BYTE * buffer, int length, BYTE srcbyte, BYTE dstbyte);
int check_bad_gcr(BYTE * gcrdata, int length, int fix);
int check_sync_flags(BYTE * gcrdata, int density, int length);
void bitshift(BYTE * gcrdata, int length, int bits);
int check_errors(BYTE * gcrdata, int length, int track, BYTE * id,
char * errorstring);
int check_empty(BYTE * gcrdata, int length, int track, BYTE * id,
char * errorstring);
int compare_tracks(BYTE * track1, BYTE * track2, int length1, int length2,
int same_disk, char * outputstring);
int compare_sectors(BYTE * track1, BYTE * track2, int length1, int length2,
BYTE * id1, BYTE * id2, int track, char * outputstring);
int strip_runs(BYTE * buffer, int length, int minrun, BYTE target);
int reduce_runs(BYTE * buffer, int length, int length_max, int minrun,
BYTE target);
int is_bad_gcr(BYTE * gcrdata, size_t length, size_t pos);
int check_formatted(BYTE * gcrdata);
int check_valid_data(BYTE * data, int length);
#endif