static void apple525_seek_disk(mess_image *img, struct apple525_disk *disk, signed int step)
{
int track;
int pseudo_track;
apple525_save_current_track(img, FALSE);
track = floppy_drive_get_current_track(img);
pseudo_track = (track * 2) + disk->tween_tracks;
pseudo_track += step;
if (pseudo_track < 0)
pseudo_track = 0;
else if (pseudo_track/2 >= APPLE2_TRACK_COUNT)
pseudo_track = APPLE2_TRACK_COUNT*2-1;
if (pseudo_track/2 != track)
{
floppy_drive_seek(img, pseudo_track/2 - floppy_drive_get_current_track(img));
disk->track_loaded = 0;
}
if (pseudo_track & 1)
disk->tween_tracks = 1;
else
disk->tween_tracks = 0;
}
static void apple525_disk_set_lines(mess_image *image, UINT8 new_state)
{
struct apple525_disk *cur_disk;
UINT8 old_state;
unsigned int phase;
cur_disk = (struct apple525_disk *) image_lookuptag(image, APPLE525TAG);
old_state = cur_disk->state;
cur_disk->state = new_state;
if ((new_state & 0x0F) > (old_state & 0x0F))
{
phase = 0;
switch((old_state ^ new_state) & 0x0F)
{
case 1: phase = 0; break;
case 2: phase = 1; break;
case 4: phase = 2; break;
case 8: phase = 3; break;
}
phase -= floppy_drive_get_current_track(image) * 2;
if (cur_disk->tween_tracks)
phase--;
phase %= 4;
switch(phase)
{
case 1:
apple525_seek_disk(image, cur_disk, +1);
break;
case 3:
apple525_seek_disk(image, cur_disk, -1);
break;
}
}
}
static void apple525_disk_set_lines(device_t *device,device_t *image, UINT8 new_state)
{
apple525_floppy_image_device *cur_disk;
UINT8 old_state;
unsigned int phase;
cur_disk = get_device(image);
old_state = cur_disk->state;
cur_disk->state = new_state;
if ((new_state & 0x0F) > (old_state & 0x0F))
{
phase = 0;
switch((old_state ^ new_state) & 0x0F)
{
case 1: phase = 0; break;
case 2: phase = 1; break;
case 4: phase = 2; break;
case 8: phase = 3; break;
}
phase -= floppy_drive_get_current_track(image) * 2;
if (cur_disk->tween_tracks)
phase--;
phase %= 4;
switch(phase)
{
case 1:
apple525_seek_disk(image, +1);
break;
case 3:
apple525_seek_disk(image, -1);
break;
}
}
}
/* Seek Track Zero bottom half */
static void mc6843_finish_STZ( device_t *device )
{
mc6843_t* mc6843 = get_safe_token( device );
device_t* img = mc6843_floppy_image( device );
int i;
/* seek to track zero */
for ( i=0; i<83; i++ )
{
if (floppy_tk00_r(img) == CLEAR_LINE)
break;
floppy_drive_seek( img, -1 );
}
LOG(( "%f mc6843_finish_STZ: actual=%i\n", device->machine().time().as_double(), floppy_drive_get_current_track( img ) ));
/* update state */
mc6843->CTAR = 0;
mc6843->GCR = 0;
mc6843->SAR = 0;
mc6843->STRB |= floppy_tk00_r(img) << 4;
mc6843_cmd_end( device );
}
/* Seek bottom half */
static void mc6843_finish_SEK( device_t *device )
{
mc6843_t* mc6843 = get_safe_token( device );
device_t* img = mc6843_floppy_image( device );
/* seek to track */
floppy_drive_seek( img, mc6843->GCR - mc6843->CTAR );
LOG(( "%f mc6843_finish_SEK: from %i to %i (actual=%i)\n", device->machine().time().as_double(), mc6843->CTAR, mc6843->GCR, floppy_drive_get_current_track( img ) ));
/* update state */
mc6843->CTAR = mc6843->GCR;
mc6843->SAR = 0;
mc6843_cmd_end( device );
}
