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-rw-r--r--blastem.c51
1 files changed, 31 insertions, 20 deletions
diff --git a/blastem.c b/blastem.c
index 559ba32..e6c6206 100644
--- a/blastem.c
+++ b/blastem.c
@@ -12,9 +12,15 @@
#define CARTRIDGE_WORDS 0x200000
#define RAM_WORDS 32 * 1024
#define Z80_RAM_BYTES 8 * 1024
+
+#define MCLKS_NTSC 53693175
+#define MCLKS_PAL 53203395
+
#define MCLKS_PER_68K 7
+#define MCLKS_PER_YM MCLKS_PER_68K
#define MCLKS_PER_Z80 15
#define MCLKS_PER_PSG (MCLKS_PER_Z80*16)
+
//TODO: Figure out the exact value for this
#define CYCLE_NEVER 0xFFFFFFFF
#define LINES_NTSC 262
@@ -187,6 +193,16 @@ void sync_z80(z80_context * z_context, uint32_t mclks)
z_context->current_cycle = mclks / MCLKS_PER_Z80;
}
}
+
+void sync_sound(genesis_context * gen, uint32_t target)
+{
+ //printf("YM | Cycle: %d, bpos: %d, PSG | Cycle: %d, bpos: %d\n", gen->ym->current_cycle, gen->ym->buffer_pos, gen->psg->cycles, gen->psg->buffer_pos * 2);
+ psg_run(gen->psg, target);
+ ym_run(gen->ym, target);
+
+ //printf("Target: %d, YM bufferpos: %d, PSG bufferpos: %d\n", target, gen->ym->buffer_pos, gen->psg->buffer_pos * 2);
+}
+
uint32_t frame=0;
m68k_context * sync_components(m68k_context * context, uint32_t address)
{
@@ -197,15 +213,15 @@ m68k_context * sync_components(m68k_context * context, uint32_t address)
uint32_t mclks = context->current_cycle * MCLKS_PER_68K;
sync_z80(z_context, mclks);
if (mclks >= mclks_per_frame) {
- ym_run(gen->ym, context->current_cycle);
- gen->ym->current_cycle -= mclks_per_frame/MCLKS_PER_68K;
+ sync_sound(gen, mclks);
+ gen->ym->current_cycle -= mclks_per_frame;
+ gen->psg->cycles -= mclks_per_frame;
if (gen->ym->write_cycle != CYCLE_NEVER) {
gen->ym->write_cycle = gen->ym->write_cycle >= mclks_per_frame/MCLKS_PER_68K ? gen->ym->write_cycle - mclks_per_frame/MCLKS_PER_68K : 0;
}
//printf("reached frame end | 68K Cycles: %d, MCLK Cycles: %d\n", context->current_cycle, mclks);
vdp_run_context(v_context, mclks_per_frame);
- psg_run(gen->psg, mclks/MCLKS_PER_PSG);
- gen->psg->cycles -= mclks_per_frame/MCLKS_PER_PSG;
+
if (!headless) {
break_on_sync |= wait_render_frame(v_context, frame_limit);
}
@@ -234,7 +250,7 @@ m68k_context * sync_components(m68k_context * context, uint32_t address)
} else {
//printf("running VDP for %d cycles\n", mclks - v_context->cycles);
vdp_run_context(v_context, mclks);
- psg_run(gen->psg, mclks/MCLKS_PER_PSG);
+ sync_sound(gen, mclks);
}
if (context->int_ack) {
vdp_int_ack(v_context, context->int_ack);
@@ -326,7 +342,7 @@ m68k_context * vdp_port_write(uint32_t vdp_port, m68k_context * context, uint16_
}
} else if (vdp_port < 0x18) {
genesis_context * gen = context->system;
- psg_run(gen->psg, (context->current_cycle * MCLKS_PER_68K) / MCLKS_PER_PSG);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_68K);
psg_write(gen->psg, value);
} else {
//TODO: Implement undocumented test register(s)
@@ -358,7 +374,7 @@ z80_context * z80_vdp_port_write(uint16_t vdp_port, z80_context * context, uint8
exit(1);
}
} else if (vdp_port < 0x18) {
- psg_run(gen->psg, (context->current_cycle * MCLKS_PER_Z80) / MCLKS_PER_PSG);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_Z80);
psg_write(gen->psg, value);
} else {
//TODO: Implement undocumented test register(s)
@@ -494,7 +510,7 @@ m68k_context * io_write(uint32_t location, m68k_context * context, uint8_t value
z80_ram[location & 0x1FFF] = value;
z80_handle_code_write(location & 0x1FFF, gen->z80);
} else if (location < 0x6000) {
- ym_run(gen->ym, context->current_cycle);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_68K);
if (location & 1) {
ym_data_write(gen->ym, value);
} else if(location & 2) {
@@ -594,7 +610,7 @@ m68k_context * io_write_w(uint32_t location, m68k_context * context, uint16_t va
z80_ram[location & 0x1FFE] = value >> 8;
z80_handle_code_write(location & 0x1FFE, gen->z80);
} else if (location < 0x6000) {
- ym_run(gen->ym, context->current_cycle);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_68K);
if (location & 1) {
ym_data_write(gen->ym, value >> 8);
} else if(location & 2) {
@@ -700,7 +716,7 @@ uint8_t io_read(uint32_t location, m68k_context * context)
if (location < 0x4000) {
value = z80_ram[location & 0x1FFF];
} else if (location < 0x6000) {
- ym_run(gen->ym, context->current_cycle);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_68K);
value = ym_read_status(gen->ym);
} else {
value = 0xFF;
@@ -767,7 +783,7 @@ uint16_t io_read_w(uint32_t location, m68k_context * context)
if (location < 0x4000) {
value = z80_ram[location & 0x1FFE];
} else if (location < 0x6000) {
- ym_run(gen->ym, context->current_cycle);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_68K);
value = ym_read_status(gen->ym);
} else {
value = 0xFF;
@@ -830,7 +846,7 @@ uint16_t io_read_w(uint32_t location, m68k_context * context)
z80_context * z80_write_ym(uint16_t location, z80_context * context, uint8_t value)
{
genesis_context * gen = context->system;
- ym_run(gen->ym, (context->current_cycle * MCLKS_PER_Z80) / MCLKS_PER_68K);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_Z80);
if (location & 1) {
ym_data_write(gen->ym, value);
} else if (location & 2) {
@@ -844,7 +860,7 @@ z80_context * z80_write_ym(uint16_t location, z80_context * context, uint8_t val
uint8_t z80_read_ym(uint16_t location, z80_context * context)
{
genesis_context * gen = context->system;
- ym_run(gen->ym, (context->current_cycle * MCLKS_PER_Z80) / MCLKS_PER_68K);
+ sync_sound(gen, context->current_cycle * MCLKS_PER_Z80);
return ym_read_status(gen->ym);
}
@@ -1810,11 +1826,6 @@ void detect_region()
}
}
-#define PSG_CLKS_NTSC (3579545/16)
-#define PSG_CLKS_PAL (3546893/16)
-#define YM_CLKS_NTSC 7670454
-#define YM_CLKS_PAL 7600485
-
int main(int argc, char ** argv)
{
if (argc < 2) {
@@ -1899,10 +1910,10 @@ int main(int argc, char ** argv)
init_vdp_context(&v_context);
ym2612_context y_context;
- ym_init(&y_context, render_sample_rate(), fps == 60 ? YM_CLKS_NTSC : YM_CLKS_PAL, render_audio_buffer());
+ ym_init(&y_context, render_sample_rate(), fps == 60 ? MCLKS_NTSC : MCLKS_PAL, MCLKS_PER_YM, render_audio_buffer());
psg_context p_context;
- psg_init(&p_context, render_sample_rate(), fps == 60 ? PSG_CLKS_NTSC : PSG_CLKS_PAL, render_audio_buffer());
+ psg_init(&p_context, render_sample_rate(), fps == 60 ? MCLKS_NTSC : MCLKS_PAL, MCLKS_PER_PSG, render_audio_buffer());
z80_context z_context;
x86_z80_options z_opts;
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-19 18:13:20 +0000