More NR43 obscurities
@@ -762,7 +762,7 @@ static inline uint16_t effective_channel4_counter(GB_gameboy_t *gb)
// case GB_MODEL_CGB_A:
case GB_MODEL_CGB_C:
if (effective_counter & 8) {
- effective_counter |= 0xE;
+ effective_counter |= 0xE; // Sometimes F on some instances
}
if (effective_counter & 0x80) {
effective_counter |= 0xFF;
@@ -777,6 +777,9 @@ static inline uint16_t effective_channel4_counter(GB_gameboy_t *gb)
effective_counter |= 0x4;
}
if (effective_counter & 0x800) {
+ if ((gb->io_registers[GB_IO_NR43] & 8)) {
+ effective_counter |= 0x400;
+ }
effective_counter |= 0x8;
}
if (effective_counter & 0x1000) {
@@ -788,7 +791,7 @@ static inline uint16_t effective_channel4_counter(GB_gameboy_t *gb)
break;
#if 0
case GB_MODEL_CGB_D:
- if (effective_counter & 0x40) {
+ if (effective_counter & ((gb->io_registers[GB_IO_NR43] & 8) ?0x80 : 0x40)) { // This is so weird
effective_counter |= 0xFF;
}
if (effective_counter & 0x100) {
@@ -809,7 +812,7 @@ static inline uint16_t effective_channel4_counter(GB_gameboy_t *gb)
break;
#endif
case GB_MODEL_CGB_E:
- if (effective_counter & 0x40) {
+ if (effective_counter & ((gb->io_registers[GB_IO_NR43] & 8) ?0x80 : 0x40)) { // This is so weird
effective_counter |= 0xFF;
}
if (effective_counter & 0x1000) {
@@ -822,7 +825,7 @@ static inline uint16_t effective_channel4_counter(GB_gameboy_t *gb)
/* For the most part, AGS seems to do:
0x20 -> 0xA0
0x200 -> 0xA00
- 0x1000 -> 0x1010
+ 0x1000 -> 0x1010, but only if wide
*/
break;
}
@@ -1250,8 +1253,9 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
}
}
- /* TODO: These two are quite weird. Verify further */
- if (gb->model <= GB_MODEL_CGB_C && gb->cgb_double_speed) {
+ /* TODO: These are quite weird. Verify further */
+ if (gb->model <= GB_MODEL_CGB_C) {
+ if (gb->cgb_double_speed) {
if (!(gb->io_registers[GB_IO_NR43] & 0xF0) && (gb->io_registers[GB_IO_NR43] & 0x07)) {
gb->apu.noise_channel.counter_countdown -= 1;
}
@@ -1259,6 +1263,10 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
gb->apu.noise_channel.counter_countdown += 1;
}
}
+ else {
+ gb->apu.noise_channel.counter_countdown -= 2;
+ }
+ }
gb->apu.noise_channel.current_volume = gb->io_registers[GB_IO_NR42] >> 4;
