unsigned long long dosamp_FAR dosamp_time_source_8254_poll(dosamp_time_source_t inst) {
if (inst->open_flags == 0) return 0UL;
if (ts_8254_pper == t8254_counter[T8254_TIMER_INTERRUPT_TICK]) {
uint16_t ncnt = read_8254(T8254_TIMER_INTERRUPT_TICK);
uint16_t delta;
/* NTS: remember the timer chip counts DOWN to zero.
* so normally, ncnt < ts_8254_pcnt unless 16-bit rollover happened. */
if (ncnt <= ts_8254_pcnt)
delta = ts_8254_pcnt - ncnt;
else
delta = ts_8254_pcnt + (uint16_t)ts_8254_pper - ncnt;
/* count */
inst->counter += (unsigned long long)delta;
/* store the prev counter */
ts_8254_pcnt = ncnt;
}
else {
ts_8254_pcnt = read_8254(T8254_TIMER_INTERRUPT_TICK);
ts_8254_pper = t8254_counter[T8254_TIMER_INTERRUPT_TICK];
}
return inst->counter;
}
int dosamp_FAR dosamp_time_source_8254_open(dosamp_time_source_t inst) {
inst->open_flags = (unsigned int)(-1);
inst->clock_rate = T8254_REF_CLOCK_HZ;
ts_8254_pcnt = read_8254(T8254_TIMER_INTERRUPT_TICK);
ts_8254_pper = t8254_counter[T8254_TIMER_INTERRUPT_TICK];
#if defined(TARGET_PC98)
assert(inst->clock_rate != 0ul); // blow up here if someone forgot to probe the 8254
#endif
return 0;
}
void play_sfx(const pcspkt_ent_list *pl) {
struct pcspk_ent *p;
t8254_time_t pc,cc;
t8254_time_t delta;
int32_t tim = 0;
p = *(pl++);
cc = read_8254(0);
while (p != NULL) {
while (p->delay != 0) {
if (p->freq != 0) {
#ifdef TARGET_PC98 /* Double the counter to convert IBM PC timer delay (1193182Hz) to PC-98 timer delay (2457600Hz) */
write_8254_pc_speaker(p->freq << 9u);
#else
write_8254_pc_speaker(p->freq << 8u);
#endif
t8254_pc_speaker_set_gate(PC_SPEAKER_GATE_ON);
}
else {
t8254_pc_speaker_set_gate(PC_SPEAKER_GATE_OFF);
}
#ifdef TARGET_PC98 /* Double the delay to convert IBM PC timer delay (1193182Hz) to PC-98 timer delay (2457600Hz) */
tim += (int32_t)((unsigned long)p->delay << 9u);
#else
tim += (int32_t)((unsigned int)p->delay << 8u);
#endif
while (tim >= 0l) {
pc = cc;
cc = read_8254(0);
delta = (pc - cc) & 0xFFFFul; /* counts DOWN */
tim -= delta;
}
p++;
}
p = *(pl++);
}
t8254_pc_speaker_set_gate(PC_SPEAKER_GATE_OFF);
}
void t8254_wait(unsigned long ticks) {
t8254_time_t pr,cr;
uint16_t dec;
if (ticks <= 1) return;
ticks--;
cr = read_8254(0);
do {
/* NTS: remember the 8254 counts downward, not upward */
pr = cr;
cr = read_8254(0);
if (cr > pr) /* when counter reaches zero it resets to the original counter value and begins counting again */
dec = (pr + (uint16_t)t8254_counter[0] - cr);
else
dec = (pr - cr);
ticks -= dec;
} while ((signed long)ticks >= 0L);
}
void direct_dac_test(void) {
unsigned long time,bytes;
unsigned char FAR *ptr;
unsigned int i,count;
unsigned int pc,c;
doubleprintf("Direct DAC playback test.\n");
/* FIXME: Why is the final rate SLOWER in DOSBox-X in 386 protected mode? */
sndsb_reset_dsp(sb_card);
sndsb_write_dsp(sb_card,0xD1); /* speaker on */
_cli();
time = 0;
bytes = 0;
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
for (count=0;count < 3;count++) {
ptr = sb_dma->lin;
for (i=0;i < sb_dma->length;i++) {
sndsb_write_dsp(sb_card,SNDSB_DSPCMD_DIRECT_DAC_OUT); /* 0x10 */
sndsb_write_dsp(sb_card,*ptr++);
pc = c;
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
time += (unsigned long)((pc - c) & 0xFFFFU); /* remember: it counts DOWN. assumes full 16-bit count */
}
bytes += sb_dma->length;
}
_sti();
if (time == 0UL) time = 1;
{
double t = (double)time / T8254_REF_CLOCK_HZ;
double rate = (double)bytes / t;
doubleprintf(" - %lu bytes played in %.3f seconds\n",(unsigned long)bytes,t);
doubleprintf(" - Sample rate is %.3fHz\n",rate);
}
}
void sb1_sc_play_adpcm2_test(void) {
unsigned long time,bytes,expect,tlen,timeout;
unsigned int count;
unsigned int pc,c;
unsigned long d;
uint32_t irqc;
doubleprintf("SB 1.x ADPCM 2-bit single cycle DSP playback test.\n");
timeout = T8254_REF_CLOCK_HZ * 4UL;
for (count=0;count < 256;count++) {
expect = 1000000UL / (unsigned long)(256 - count);
_cli();
if (sb_card->irq >= 8) {
p8259_OCW2(8,P8259_OCW2_SPECIFIC_EOI | (sb_card->irq & 7));
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | 2);
}
else if (sb_card->irq >= 0) {
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | sb_card->irq);
}
_sti();
tlen = (expect / 4UL) + 1; // 1 sec
if (tlen > sb_card->buffer_size) tlen = sb_card->buffer_size;
sb_card->buffer_dma_started_length = tlen;
sb_card->buffer_dma_started = 0;
sndsb_reset_dsp(sb_card);
sndsb_write_dsp(sb_card,0xD1); /* speaker on */
sndsb_setup_dma(sb_card);
irqc = sb_card->irq_counter;
sndsb_write_dsp_timeconst(sb_card,count);
_cli();
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
bytes = tlen;
time = 0;
_sti();
{
unsigned int lv = (unsigned int)(tlen - 1UL);
sndsb_write_dsp(sb_card,SNDSB_DSPCMD_DMA_DAC_OUT_ADPCM_2BIT_REF); /* 0x17 */
sndsb_write_dsp(sb_card,lv);
sndsb_write_dsp(sb_card,lv >> 8);
}
while (1) {
if (irqc != sb_card->irq_counter)
break;
_cli();
pc = c;
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
time += (unsigned long)((pc - c) & 0xFFFFU); /* remember: it counts DOWN. assumes full 16-bit count */
_sti();
if (time >= timeout) goto x_timeout;
}
x_complete:
if (time == 0UL) time = 1;
{
double t = (double)time / T8254_REF_CLOCK_HZ;
double rate = (double)(((bytes - 1UL) * 4UL) + 1UL) / t; /* 4 samples/byte + 1 reference */
doubleprintf(" - TC 0x%02X: expecting %luHz, %lub/%.3fs @ %.3fHz\n",count,expect,(unsigned long)bytes,t,rate);
}
if (kbhit()) {
if (getch() == 27)
break;
}
continue;
x_timeout:
d = d8237_read_count(sb_card->dma8); /* counts DOWNWARD */
if (d > tlen) d = 0; /* terminal count */
d = tlen - d;
if (irqc == sb_card->irq_counter && d == 0) bytes = 0; /* nothing happened if no IRQ and counter never changed */
else if (bytes > d) bytes = d;
goto x_complete;
}
_cli();
if (sb_card->irq >= 8) {
p8259_OCW2(8,P8259_OCW2_SPECIFIC_EOI | (sb_card->irq & 7));
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | 2);
}
else if (sb_card->irq >= 0) {
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | sb_card->irq);
}
_sti();
sndsb_write_dsp_timeconst(sb_card,0x83); /* 8000Hz */
sndsb_reset_dsp(sb_card);
}
void sb16_sc_play_test(void) {
unsigned char bytespersample = wav_16bit ? 2 : 1;
unsigned long time,bytes,expect,tlen,timeout;
unsigned long count;
unsigned int pc,c;
unsigned long d;
uint32_t irqc;
int dma;
if (wav_16bit && sb_card->dma16 >= 4)
dma = sb_card->dma16;
else
dma = sb_card->dma8;
if (sb_card->dsp_vmaj >= 4) /* Sound Blaster 16 */
{ }
else if (sb_card->is_gallant_sc6600) /* Reveal SC-4000 / Gallant SC-6600 */
{ }
else
return;
doubleprintf("SB16 4.x single cycle DSP playback test (%u bit).\n",wav_16bit?16:8);
timeout = T8254_REF_CLOCK_HZ * 2UL;
count = 0;
do {
expect = count;
_cli();
if (sb_card->irq >= 8) {
p8259_OCW2(8,P8259_OCW2_SPECIFIC_EOI | (sb_card->irq & 7));
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | 2);
}
else if (sb_card->irq >= 0) {
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | sb_card->irq);
}
_sti();
tlen = expect; // 1 sec
if (tlen < 4000UL) tlen = 4000UL;
if (tlen > (sb_card->buffer_size / (unsigned long)bytespersample)) tlen = sb_card->buffer_size / (unsigned long)bytespersample;
sb_card->buffer_dma_started_length = tlen * (unsigned long)bytespersample;
sb_card->buffer_dma_started = 0;
sndsb_reset_dsp(sb_card);
sndsb_write_dsp(sb_card,0xD1); /* speaker on */
sndsb_setup_dma(sb_card);
irqc = sb_card->irq_counter;
sndsb_write_dsp_outrate(sb_card,count);
_cli();
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
bytes = tlen;
time = 0;
_sti();
{
unsigned int lv = (unsigned int)(tlen - 1UL);
/* NTS: Reveal SC-4000 (Gallant 6600) cards DO support SB16 but only specific commands.
* Command 0xC0 is not recognized, but command 0xC6 works. */
if (wav_16bit) {
if (sb_card->is_gallant_sc6600)
sndsb_write_dsp(sb_card,SNDSB_DSPCMD_SB16_AUTOINIT_DMA_DAC_OUT_16BIT); /* 0xB6 */
else
sndsb_write_dsp(sb_card,SNDSB_DSPCMD_SB16_DMA_DAC_OUT_16BIT); /* 0xB0 */
sndsb_write_dsp(sb_card,0x10); /* mode (16-bit signed PCM) */
}
else {
if (sb_card->is_gallant_sc6600)
sndsb_write_dsp(sb_card,SNDSB_DSPCMD_SB16_AUTOINIT_DMA_DAC_OUT_8BIT); /* 0xC6 */
else
sndsb_write_dsp(sb_card,SNDSB_DSPCMD_SB16_DMA_DAC_OUT_8BIT); /* 0xC0 */
sndsb_write_dsp(sb_card,0x00); /* mode (8-bit unsigned PCM) */
}
sndsb_write_dsp(sb_card,lv);
sndsb_write_dsp(sb_card,lv >> 8);
}
while (1) {
if (irqc != sb_card->irq_counter)
break;
_cli();
pc = c;
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
time += (unsigned long)((pc - c) & 0xFFFFU); /* remember: it counts DOWN. assumes full 16-bit count */
_sti();
if (time >= timeout) goto x_timeout;
}
x_complete:
if (time == 0UL) time = 1;
{
double t = (double)time / T8254_REF_CLOCK_HZ;
double rate = (double)bytes / t;
doubleprintf(" - Rate 0x%04lX: expecting %luHz, %lu%c/%.3fs @ %.3fHz\n",count,expect,(unsigned long)bytes,wav_16bit?'w':'b',t,rate);
}
if (kbhit()) {
if (getch() == 27)
break;
}
count += 0x80; /* count by 128 because enumerating all would take too long */
if (count > 0xFFFFUL) break;
continue;
x_timeout:
d = d8237_read_count(dma) / (unsigned long)bytespersample; /* counts DOWNWARD */
if (d > tlen) d = 0; /* terminal count */
d = tlen - d;
if (irqc == sb_card->irq_counter && d == 0) bytes = 0; /* nothing happened if no IRQ and counter never changed */
else if (bytes > d) bytes = d;
goto x_complete;
} while (1);
_cli();
if (sb_card->irq >= 8) {
p8259_OCW2(8,P8259_OCW2_SPECIFIC_EOI | (sb_card->irq & 7));
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | 2);
}
else if (sb_card->irq >= 0) {
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | sb_card->irq);
}
_sti();
sndsb_reset_dsp(sb_card);
sndsb_write_dsp_outrate(sb_card,8000U);
}
void ess_sc_play_test(void) {
unsigned char bytespersample = wav_16bit ? 2 : 1;
unsigned long time,bytes,expect,tlen,timeout;
unsigned long count;
unsigned int pc,c;
unsigned long d;
uint32_t irqc;
if (!sb_card->ess_extensions || sb_card->ess_chipset == 0)
return;
doubleprintf("ESS688 single cycle DSP playback test (%u bit).\n",wav_16bit?16:8);
timeout = T8254_REF_CLOCK_HZ * 2UL;
for (count=0;count < 256;count++) {
if (count >= 128)
expect = 795500UL / (256 - count);
else
expect = 397700UL / (128 - count);
_cli();
if (sb_card->irq >= 8) {
p8259_OCW2(8,P8259_OCW2_SPECIFIC_EOI | (sb_card->irq & 7));
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | 2);
}
else if (sb_card->irq >= 0) {
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | sb_card->irq);
}
_sti();
tlen = expect; // 1 sec
if (tlen > (sb_card->buffer_size / (unsigned long)bytespersample)) tlen = sb_card->buffer_size / (unsigned long)bytespersample;
/* NTS: We ask the card to use demand ISA, 4 bytes at a time.
* Behavior observed on real hardware, is that if you set up
* DMA this way and then set up a non-auto-init DMA transfer
* that isn't a multiple of 4, the DMA will stop short of
* the full transfer and the IRQ will never fire. Therefore
* the transfer length must be a multiple of 4! */
tlen -= tlen & 3;
if (tlen == 0) tlen = 4;
sb_card->buffer_dma_started_length = tlen * (unsigned long)bytespersample;
sb_card->buffer_dma_started = 0;
sndsb_reset_dsp(sb_card);
sndsb_write_dsp(sb_card,0xD1); /* speaker on */
sndsb_ess_set_extended_mode(sb_card,1/*enable*/);
sndsb_setup_dma(sb_card);
irqc = sb_card->irq_counter;
{
/* ESS 688/1869 chipset specific DSP playback.
using this mode bypasses a lot of the Sound Blaster Pro emulation
and restrictions and allows us to run up to 48KHz 16-bit stereo */
unsigned short t16;
int b;
_cli();
/* clear IRQ */
sndsb_interrupt_ack(sb_card,3);
b = 0x00; /* DMA disable */
b |= 0x00; /* no auto-init */
b |= 0x00; /* [3]=DMA converter in ADC mode [1]=DMA read for ADC playback mode */
sndsb_ess_write_controller(sb_card,0xB8,b);
b = sndsb_ess_read_controller(sb_card,0xA8);
b &= ~0xB; /* clear mono/stereo and record monitor (bits 3, 1, and 0) */
b |= 2; /* mono 10=mono 01=stereo */
sndsb_ess_write_controller(sb_card,0xA8,b);
/* NTS: The meaning of bits 1:0 in register 0xB9
*
* 00 single DMA transfer mode
* 01 demand DMA transfer mode, 2 bytes/request
* 10 demand DMA transfer mode, 4 bytes/request
* 11 reserved
*
* NOTES on what happens if you set bits 1:0 (DMA transfer type) to the "reserved" 11 value:
*
* ESS 688 (Sharp laptop) Nothing, apparently. Treated the same as 4 bytes/request
*
* ESS 1887 (Compaq Presario) Triggers a hardware bug where the chip appears to fetch
* 3 bytes per demand transfer but then only handle 1 byte,
* which translates to audio playing at 3x the sample rate
* it should be. NOT because the DAC is running any faster,
* but because the chip is only playing back every 3rd sample!
* This play only 3rds behavior is consistent across 8/16-bit
* PCM and mono/stereo.
*/
b = 2; /* demand transfer DMA 4 bytes per request */
sndsb_ess_write_controller(sb_card,0xB9,b);
sndsb_ess_write_controller(sb_card,0xA1,count);
/* effectively disable the lowpass filter (NTS: 0xFF mutes the audio, apparently) */
sndsb_ess_write_controller(sb_card,0xA2,0xFE);
t16 = -(tlen * (uint16_t)bytespersample); /* DMA transfer count reload register value is 2's complement of length */
sndsb_ess_write_controller(sb_card,0xA4,t16); /* DMA transfer count low */
sndsb_ess_write_controller(sb_card,0xA5,t16>>8); /* DMA transfer count high */
b = sndsb_ess_read_controller(sb_card,0xB1);
b &= ~0xA0; /* clear compat game IRQ, fifo half-empty IRQs */
b |= 0x50; /* set overflow IRQ, and "no function" */
sndsb_ess_write_controller(sb_card,0xB1,b);
b = sndsb_ess_read_controller(sb_card,0xB2);
b &= ~0xA0; /* clear compat */
b |= 0x50; /* set DRQ/DACKB inputs for DMA */
sndsb_ess_write_controller(sb_card,0xB2,b);
b = 0x51; /* enable FIFO+DMA, reserved, load signal */
b |= wav_16bit ? 0x20 : 0x00; /* signed complement mode or not */
sndsb_ess_write_controller(sb_card,0xB7,b);
b = 0x90; /* enable FIFO+DMA, reserved, load signal */
b |= wav_16bit ? 0x20 : 0x00; /* signed complement mode or not */
b |= 0x40; /* [3]=stereo [6]=!stereo */
b |= wav_16bit ? 0x04 : 0x00; /* [2]=16bit */
sndsb_ess_write_controller(sb_card,0xB7,b);
b = sndsb_ess_read_controller(sb_card,0xB8);
sndsb_ess_write_controller(sb_card,0xB8,b | 1);
}
_cli();
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
bytes = tlen;
time = 0;
_sti();
while (1) {
if (irqc != sb_card->irq_counter)
break;
_cli();
pc = c;
c = read_8254(T8254_TIMER_INTERRUPT_TICK);
time += (unsigned long)((pc - c) & 0xFFFFU); /* remember: it counts DOWN. assumes full 16-bit count */
_sti();
if (time >= timeout) goto x_timeout;
}
x_complete:
if (time == 0UL) time = 1;
{
int b;
b = sndsb_ess_read_controller(sb_card,0xB8);
if (b != -1) {
b &= ~0x01; /* stop DMA */
sndsb_ess_write_controller(sb_card,0xB8,b);
}
}
{
double t = (double)time / T8254_REF_CLOCK_HZ;
double rate = (double)bytes / t;
doubleprintf(" - TC 0x%02lX: expecting %luHz, %lu%c/%.3fs @ %.3fHz\n",count,expect,(unsigned long)bytes,wav_16bit?'w':'b',t,rate);
}
if (kbhit()) {
if (getch() == 27)
break;
}
continue;
x_timeout:
d = d8237_read_count(sb_card->dma8) / (unsigned long)bytespersample; /* counts DOWNWARD */
if (d > tlen) d = 0; /* terminal count */
d = tlen - d;
if (irqc == sb_card->irq_counter && d == 0) bytes = 0; /* nothing happened if no IRQ and counter never changed */
else if (bytes > d) bytes = d;
goto x_complete;
}
_cli();
if (sb_card->irq >= 8) {
p8259_OCW2(8,P8259_OCW2_SPECIFIC_EOI | (sb_card->irq & 7));
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | 2);
}
else if (sb_card->irq >= 0) {
p8259_OCW2(0,P8259_OCW2_SPECIFIC_EOI | sb_card->irq);
}
_sti();
sndsb_reset_dsp(sb_card);
}
int main() {
struct t8254_readback_t readback;
t8254_time_t tick[3];
unsigned int i;
printf("8254 library test program\n");
if (!probe_8254()) {
printf("Chip not present. Your computer might be 2010-era hardware that dropped support for it.\n");
return 1;
}
if (!probe_8259()) {
printf("8259 interrupt controller not present. Your computer might be 2010-era hardware that dropped support for it.\n");
return 1;
}
printf("8254 base clock: %luHz\n",T8254_REF_CLOCK_HZ);
speaker_rate = T8254_REF_CLOCK_HZ / 400UL; /* 400Hz */
prev_irq0 = _dos_getvect(T8254_IRQ+0x08);
_dos_setvect(T8254_IRQ+0x8,irq0);
_cli();
write_8254_pc_speaker(speaker_rate);
write_8254_system_timer(max);
_sti();
#ifdef TARGET_PC98
/* PC-98 does not have IRQ0 running by default */
p8259_unmask(T8254_IRQ);
#endif
while (1) {
if (kbhit()) {
int c = getch();
if (c == 27)
break;
else if (c == '-') {
max -= 80;
if (max > (0xFFFF-80))
max = 0xFFFF;
_cli();
write_8254_system_timer(max);
_sti();
}
else if (c == '=') {
max += 110;
if (max < 110 || max > (0xFFFF-110))
max = 0xFFFF;
_cli();
write_8254_system_timer(max);
_sti();
}
/* play with timer 2 and the PC speaker gate */
else if (c == 'p') {
unsigned char on = (t8254_pc_speaker_read_gate() != 0) ? 1 : 0;
if (on) t8254_pc_speaker_set_gate(0);
else t8254_pc_speaker_set_gate(3);
}
else if (c == '1') {
#ifndef TARGET_PC98
unsigned char v = t8254_pc_speaker_read_gate();
t8254_pc_speaker_set_gate(v ^ PC_SPEAKER_OUTPUT_TTL_AND_GATE);
#endif
}
else if (c == '2') {
#ifndef TARGET_PC98
unsigned char v = t8254_pc_speaker_read_gate();
t8254_pc_speaker_set_gate(v ^ PC_SPEAKER_COUNTER_2_GATE);
#endif
}
else if (c == '[') {
speaker_rate += 110;
if (speaker_rate > (0xFFFF-110) || speaker_rate < 110)
speaker_rate = 0xFFFF;
write_8254_pc_speaker(speaker_rate);
}
else if (c == ']') {
speaker_rate -= 110;
if (speaker_rate > (0xFFFF-110))
speaker_rate = 0;
write_8254_pc_speaker(speaker_rate);
}
else if (c == 'w') {
printf("\n");
pulse_width_test();
_cli();
write_8254_system_timer(max);
_sti();
printf("\n");
}
else if (c == 'z') {
/* sleep-wait loop test */
unsigned long delay_ticks;
unsigned long z;
unsigned int c,cmax;
printf("\nDelay interval in us? ");
z = 1000000; scanf("%lu",&z);
delay_ticks = t8254_us2ticks(z);
printf(" %lu = %lu ticks\n",z,delay_ticks);
if (delay_ticks == 0UL) cmax = (unsigned int)(T8254_REF_CLOCK_HZ / 20UL);
else cmax = (unsigned int)(T8254_REF_CLOCK_HZ / 20UL / (unsigned long)delay_ticks);
if (cmax == 0) cmax = 1;
write_8254_pc_speaker(T8254_REF_CLOCK_HZ / 400UL); /* tick as fast as possible */
while (1) {
if (kbhit()) {
if (getch() == 27) break;
}
for (c=0;c < cmax;c++) {
t8254_pc_speaker_set_gate(3);
t8254_wait(delay_ticks);
t8254_pc_speaker_set_gate(0);
t8254_wait(delay_ticks);
}
}
}
else if (c == 'd') {
printf("\n \nDetail mode, hit 'd' again to exit: [WARNING: 8254 only]\n");
while (1) {
if (kbhit()) {
int c = getch();
if (c == 'd') {
break;
}
}
_cli();
readback_8254(T8254_READBACK_ALL,&readback);
_sti();
printf("\x0D");
for (i=0;i <= 2;i++) {
printf("[%u] stat=%02x count=%04x ",i,
readback.timer[i].status,
readback.timer[i].count);
}
fflush(stdout);
}
printf("\n");
}
}
for (i=0;i <= 2;i++) tick[i] = read_8254(i);
/* BUG: DOSBox/DOSBox-X appear to have a bug where the PC speaker readback toggles
* regardless of the GATE input to Counter 2. Bring GATE low (setting bit 1
* of port 61h to 0) is supposed to cause Counter 2 to stop. The AND gate
* after the output (bit 0 of port 61h) is not supposed to affect the readback. */
printf("\x0D %04x %04x %04x max=%04x count=%04x SPKR=%u",tick[0],tick[1],tick[2],
max,counter,read_8254_pc_speaker_output()!=0?1:0);
fflush(stdout);
}
printf("\n");
#ifdef TARGET_PC98
/* PC-98 does not have IRQ0 running by default */
p8259_mask(T8254_IRQ);
#endif
_cli();
write_8254_pc_speaker(0);
t8254_pc_speaker_set_gate(0);
_dos_setvect(T8254_IRQ+0x8,prev_irq0);
_sti();
write_8254_system_timer(0xFFFF); /* restore normal function to prevent BIOS from going crazy */
return 0;
}
