diff options
| -rw-r--r-- | vdp.c | 30 |
1 files changed, 22 insertions, 8 deletions
@@ -757,23 +757,35 @@ static void vdp_advance_dma(vdp_context * context) } } +void write_vram_word(vdp_context *context, uint32_t address, uint8_t value) +{ + if (!(address & 4)) { + uint32_t sat_address = (context->regs[REG_SAT] & 0xFF) << 9; + if(address >= sat_address && address < (sat_address + SAT_CACHE_SIZE*2)) { + uint16_t cache_address = address - sat_address; + cache_address = (cache_address & 3) | (cache_address >> 1 & 0x1FC); + context->sat_cache[cache_address] = value >> 8; + context->sat_cache[cache_address^1] = value; + } + } + address = (address & 0x3FC) | (address >> 1 & 0xFC01) | (address >> 9 & 0x2); + address ^= 1; + //TODO: Support an option to actually have 128KB of VRAM + context->vdpmem[address] = value; +} + void write_vram_byte(vdp_context *context, uint32_t address, uint8_t value) { if (context->regs[REG_MODE_2] & BIT_MODE_5) { - if (context->regs[REG_MODE_2] & BIT_128K_VRAM) { - address = (address & 0x3FC) | (address >> 1 & 0xFC01) | (address >> 9 & 0x2); - address ^= 1; - } else { - address &= 0xFFFF; - } if (!(address & 4)) { - uint16_t sat_address = (context->regs[REG_SAT] & 0x7F) << 9; + uint32_t sat_address = (context->regs[REG_SAT] & 0x7F) << 9; if(address >= sat_address && address < (sat_address + SAT_CACHE_SIZE*2)) { uint16_t cache_address = address - sat_address; cache_address = (cache_address & 3) | (cache_address >> 1 & 0x1FC); context->sat_cache[cache_address] = value; } } + address &= 0xFFFF; } else { address = mode4_address_map[address & 0x3FFF]; } @@ -796,7 +808,9 @@ static void external_slot(vdp_context * context) { case VRAM_WRITE: //TODO: Support actually having 128K VRAM as an option - if (start->partial || (context->regs[REG_MODE_2] & BIT_128K_VRAM)) { + if ((context->regs[REG_MODE_2] & (BIT_128K_VRAM|BIT_MODE_5)) == (BIT_128K_VRAM|BIT_MODE_5)) { + write_vram_word(context, start->address, start->value); + } else if (start->partial) { //printf("VRAM Write: %X to %X at %d (line %d, slot %d)\n", start->value, start->address ^ 1, context->cycles, context->cycles/MCLKS_LINE, (context->cycles%MCLKS_LINE)/16); write_vram_byte(context, start->address ^ 1, start->partial == 2 ? start->value >> 8 : start->value); } else { |