void datasette_set_tape_image(tap_t *image)
{
CLOCK gap;
DBG(("datasette_set_tape_image (image present:%s)", image ? "yes" : "no"));
current_image = image;
last_tap = next_tap = 0;
datasette_internal_reset();
if (image != NULL) {
/* We need the length of tape for realistic counter. */
current_image->cycle_counter_total = 0;
do {
gap = datasette_read_gap(1);
current_image->cycle_counter_total += gap / 8;
} while (gap);
current_image->current_file_seek_position = 0;
}
datasette_set_tape_sense(0);
last_tap = next_tap = 0;
fullwave = 0;
ui_set_tape_status(current_image ? 1 : 0);
}
static void datasette_read_bit(CLOCK offset, void *data)
{
double speed_of_tape = DS_V_PLAY;
int direction = 1;
long gap;
alarm_unset(datasette_alarm);
datasette_alarm_pending = 0;
if (current_image == NULL)
return;
/* check for delay of motor stop */
if (motor_stop_clk > 0 && maincpu_clk >= motor_stop_clk) {
motor_stop_clk = 0;
ui_display_tape_motor_status(0);
datasette_motor = 0;
}
if (!datasette_motor)
return;
switch (current_image->mode) {
case DATASETTE_CONTROL_START:
direction = 1;
speed_of_tape = DS_V_PLAY;
if (!datasette_long_gap_pending)
datasette_trigger_flux_change(fullwave);
break;
case DATASETTE_CONTROL_FORWARD:
direction = 1;
speed_of_tape = DS_RPS_FAST / DS_G
* sqrt(4 * PI * DS_D
* DS_V_PLAY / datasette_cycles_per_second * 8
* current_image->cycle_counter
+ 4 * PI * PI * DS_R * DS_R);
break;
case DATASETTE_CONTROL_REWIND:
direction = -1;
speed_of_tape = DS_RPS_FAST / DS_G
* sqrt(4 * PI * DS_D
* DS_V_PLAY / datasette_cycles_per_second * 8
* (current_image->cycle_counter_total
- current_image->cycle_counter)
+ 4 * PI * PI * DS_R * DS_R);
break;
case DATASETTE_CONTROL_RECORD:
case DATASETTE_CONTROL_STOP:
return;
default:
log_error(datasette_log, "Unknown datasette mode.");
return;
}
if (direction + datasette_last_direction == 0) {
/* the direction changed; read the gap from file,
but use use only the elapsed gap */
gap = datasette_read_gap(direction);
datasette_long_gap_pending = datasette_long_gap_elapsed;
datasette_long_gap_elapsed = gap - datasette_long_gap_elapsed;
}
if (datasette_long_gap_pending) {
gap = datasette_long_gap_pending;
datasette_long_gap_pending = 0;
} else {
gap = datasette_read_gap(direction);
if (gap)
datasette_long_gap_elapsed = 0;
}
if (!gap) {
datasette_control(DATASETTE_CONTROL_STOP);
return;
}
if (gap > DATASETTE_MAX_GAP) {
datasette_long_gap_pending = gap - DATASETTE_MAX_GAP;
gap = DATASETTE_MAX_GAP;
}
datasette_long_gap_elapsed += gap;
datasette_last_direction = direction;
if (direction > 0)
current_image->cycle_counter += gap / 8;
else
current_image->cycle_counter -= gap / 8;
gap -= offset;
if (gap > 0) {
alarm_set(datasette_alarm, maincpu_clk +
(CLOCK)(gap * (DS_V_PLAY / speed_of_tape)));
datasette_alarm_pending = 1;
} else {
/* If the offset is geater than the gap to the next flux
change, the change happend during DMA. Schedule it now. */
alarm_set(datasette_alarm, maincpu_clk);
datasette_alarm_pending = 1;
}
datasette_update_ui_counter();
}