Slightly improve MBC3 accuracy
@@ -190,14 +190,17 @@ static uint8_t read_mbc_ram(GB_gameboy_t *gb, uint16_t addr)
}
if (gb->cartridge_type->has_rtc && gb->cartridge_type->mbc_type != GB_HUC3 &&
- gb->mbc3_rtc_mapped && gb->mbc_ram_bank <= 4) {
+ gb->mbc3_rtc_mapped) {
/* RTC read */
+ if (gb->mbc_ram_bank <= 4) {
gb->rtc_latched.seconds &= 0x3F;
gb->rtc_latched.minutes &= 0x3F;
gb->rtc_latched.hours &= 0x1F;
gb->rtc_latched.high &= 0xC1;
return gb->rtc_latched.data[gb->mbc_ram_bank];
}
+ return 0xFF;
+ }
if (gb->camera_registers_mapped) {
return GB_camera_read_register(gb, addr);
@@ -213,6 +216,9 @@ static uint8_t read_mbc_ram(GB_gameboy_t *gb, uint16_t addr)
uint8_t effective_bank = gb->mbc_ram_bank;
if (gb->cartridge_type->mbc_type == GB_MBC3 && !gb->is_mbc30) {
+ if (gb->cartridge_type->has_rtc) {
+ if (effective_bank > 3) return 0xFF;
+ }
effective_bank &= 0x3;
}
uint8_t ret = gb->mbc_ram[((addr & 0x1FFF) + effective_bank * 0x2000) & (gb->mbc_ram_size - 1)];
@@ -695,11 +701,13 @@ static void write_mbc_ram(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
return;
}
- if (gb->cartridge_type->has_rtc && gb->mbc3_rtc_mapped && gb->mbc_ram_bank <= 4) {
+ if (gb->cartridge_type->has_rtc && gb->mbc3_rtc_mapped) {
+ if (gb->mbc_ram_bank <= 4) {
if (gb->mbc_ram_bank == 0) {
gb->rtc_cycles = 0;
}
gb->rtc_latched.data[gb->mbc_ram_bank] = gb->rtc_real.data[gb->mbc_ram_bank] = value;
+ }
return;
}
@@ -709,6 +717,9 @@ static void write_mbc_ram(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
uint8_t effective_bank = gb->mbc_ram_bank;
if (gb->cartridge_type->mbc_type == GB_MBC3 && !gb->is_mbc30) {
+ if (gb->cartridge_type->has_rtc) {
+ if (effective_bank > 3) return;
+ }
effective_bank &= 0x3;
}
