void disc_sector_reset(int drive, int side);
void disc_sector_add(int drive, int side, uint8_t c, uint8_t h, uint8_t r, uint8_t n, int rate, uint8_t *data);
void disc_sector_readsector(int drive, int sector, int track, int side, int density, int sector_size);
void disc_sector_writesector(int drive, int sector, int track, int side, int density, int sector_size);
void disc_sector_readaddress(int drive, int sector, int side, int density);
void disc_sector_format(int drive, int sector, int side, int density, uint8_t fill);
void disc_sector_stop(int drive);
int disc_sector_poll(int drive);
void disc_sector_stop(int drive);

#define length_gap0	80
#define length_gap1	50
#define length_sync	12
#define length_am	4
#define length_crc	2
#define length_gap2	22
#define length_gap3	84 // 88
#define length_gap3_0	108
#define no_sectors	15 // 8
#define no_sectors_0	18
#define raw_track_size	10416 // 6250
#define raw_track_size_0	12500

#define IBM
#define MFM
#ifdef IBM
#define pre_gap1	length_gap0 + length_sync + length_am
#else
#define pre_gap1	0
#endif
  
#define pre_track	pre_gap1 + length_gap1
#define pre_gap		length_sync + length_am + 4 + length_crc	// 22
#define pre_data	length_sync + length_am				// 16
#define data_size	512
#define post_gap	length_crc

extern int raw_tsize[2];
extern int gap2_size[2];
extern int gap3_size[2];
extern int gap4_size[2];

extern void (*disc_sector_writeback[2])(int drive, int track);