// Find the number of cylinders the disk has. We step down the disk until we
// find unreadable tracks, the cylinder number in header doesn't match, or
// seek times out. Various disks have different behavior. The tracks past the end
// leading to the park zone are normally not formated. Many drives won't let you
// seek past the last cylinder. They either return to track zero or perform a
// recalibrate which may take enough time for the seek to timeout. Really old
// disk will just hit the end stop so can get the same cylinder. Hitting end stop
// probably isn't great.
//
// drive_params: Drive parameters determined so far and return what we have determined
// start_cyl: cylinder head is on at entry
// head: head currently selected
// deltas: MFM delta time transition data to analyze (filled after read)
//
// TODO, this won't deal well with spared cylinders when they have nonsequential
// values
static void analyze_disk_size(DRIVE_PARAMS *drive_params, int start_cyl,
int head, void *deltas, int max_deltas) {
int msg_mask_hold;
int max_cyl;
int not_next_cyl, not_next_cyl_count;
int any_header_found;
int no_header_count;
SECTOR_STATUS sector_status_list[MAX_SECTORS];
int cyl;
int i;
int last_printed_cyl;
max_cyl = 0;
no_header_count = 0;
not_next_cyl_count = 0;
for (cyl = start_cyl + 1; cyl < MAX_CYL; cyl++) {
if (cyl % 5 == 0)
msg(MSG_PROGRESS, "At cyl %d\r", cyl);
if (drive_step(drive_params->step_speed, 1,
DRIVE_STEP_UPDATE_CYL, DRIVE_STEP_RET_ERR) != 0) {
msg(MSG_INFO, "Max cylinder set from drive timeout on seek\n");
break;
}
drive_read_track(drive_params, cyl, head, deltas, max_deltas);
mfm_init_sector_status_list(sector_status_list, drive_params->num_sectors);
msg_mask_hold = msg_set_err_mask(decode_errors);
mfm_decode_track(drive_params, cyl, head, deltas, NULL, sector_status_list);
msg_set_err_mask(msg_mask_hold);
any_header_found = 0;
not_next_cyl = 0;
last_printed_cyl = -1;
for (i = 0; i < drive_params->num_sectors; i++) {
if (sector_status_list[i].status & SECT_HEADER_FOUND) {
any_header_found = 1;
max_cyl = MAX(max_cyl, sector_status_list[i].cyl);
if (cyl != sector_status_list[i].cyl && last_printed_cyl != cyl) {
msg(MSG_INFO, "Found cylinder %d expected %d\n",sector_status_list[i].cyl, cyl);
last_printed_cyl = cyl;
not_next_cyl = 1;
}
}
}
if (!any_header_found) {
if (++no_header_count >= 2) {
msg(MSG_INFO, "Stopping end of disk search due to two unreadable tracks in a row\n");
break;
} else {
msg(MSG_INFO, "No sectors readable from cylinder %d\n",cyl);
}
} else {
no_header_count = 0;
}
if (not_next_cyl) {
if (++not_next_cyl_count >= 2) {
msg(MSG_INFO, "Stopping end of disk search due to mismatching cylinder count\n");
break;
}
} else {
not_next_cyl_count = 0;
}
}
drive_params->num_cyl = max_cyl + 1;
msg(MSG_INFO, "Number of cylinders %d, %.1f MB\n", drive_params->num_cyl,
(double) drive_params->num_cyl * drive_params->num_head *
drive_params->num_sectors * drive_params->sector_size / (1000.0*1000));
// We don't know where head is so return to 0
drive_seek_track0();
}
static void process_cmd( wd1793_t *device )
{
unsigned char cmd = device->command;
if ( (cmd & 0x80) == 0 )
{
// type I command
device->status = STAT_BUSY;
device->out_status &= ~(WD1793_DRQ | WD1793_INTRQ);
if ( FLAG_H(cmd) )
device->out_status |= WD1793_HLD;
else
device->out_status &= ~WD1793_HLD;
if ( (cmd & 0xE0) == 0 )
{
// seek and restore commands
if ( (cmd & 0x10) == 0 )
{
// restore command
device->track = 0xFF;
device->data = 0;
}
device->dsr = device->data;
while ( device->dsr != device->track )
{
if ( device->dsr > device->track )
{
device->out_status |= WD1793_DIR;
device->track ++;
}
else
{
device->out_status &= ~WD1793_DIR;
device->track --;
}
drive_step( device );
}
}
else
{
// step commands
if ( (cmd & 0x60) == 4 ) // step in
device->out_status |= WD1793_DIR;
else if ( (cmd & 0x60) == 6 ) // step out
device->out_status &= ~WD1793_DIR;
if ( FLAG_U(cmd) )
{
if ( device->out_status & WD1793_DIR )
device->track ++;
else
device->track --;
}
drive_step( device );
}
/*if ( !(device->out_status & WD1793_DIR) && (device->disk.track == 0) )
{
device->track = 0;
device->count = 1; // no delay
}
else
{
drive_step( device );
device->count = pos_delays[FLAG_R(cmd)];
}*/
device->state = WD1793_TYPE1;
// HACK
device->status &= ~(STAT_BUSY | STAT_TRACK_0);
if ( device->disk.track == 0 )
{
device->status |= STAT_TRACK_0;
device->track = 0;
}
device->out_status |= WD1793_INTRQ;
}
else if ( (cmd & 0x40) == 0 )
{
// type II command
device->status |= STAT_BUSY;
}
else if ( (cmd & 0x30) == 0x01 )
{
// type IV command
device->status &= ~STAT_BUSY;
}
else
{
// type III command
device->status |= STAT_BUSY;
}
}