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PCE: Support homebrew CD-ROM marker to automatically select SuperGrafx mode #150

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Merged
Fiskbit merged 1 commit into from
May 30, 2026
Merged

PCE: Support homebrew CD-ROM marker to automatically select SuperGrafx mode #150

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26 changes: 26 additions & 0 deletions Core/PCE/PceConsole.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,10 @@ LoadRomResult PceConsole::LoadRom(VirtualFile& romFile)
return LoadRomResult::Failure;
}

if(consoleType == PceConsoleType::Auto && IsSuperGrafxCd(disc)) {
consoleType = PceConsoleType::SuperGrafx;
}

_cdrom.reset(new PceCdRom(_emu, this, disc));
_romFormat = RomFormat::PceCdRom;
cdromUnitEnabled = true;
Expand Down Expand Up @@ -136,6 +140,9 @@ LoadRomResult PceConsole::LoadRom(VirtualFile& romFile)

MessageManager::Log("-----------------");
MessageManager::Log("Loaded: " + romFile.GetFileName());
if(consoleType == PceConsoleType::SuperGrafx && cfg.ConsoleType == PceConsoleType::Auto) {
MessageManager::Log("Enabled SuperGrafx mode (auto-detect)");
}
MessageManager::Log("-----------------");

return LoadRomResult::Success;
Expand All @@ -161,6 +168,25 @@ bool PceConsole::IsPopulousCard(uint32_t crc32)
return crc32 == 0x083C956A;
}

bool PceConsole::IsSuperGrafxCd(DiscInfo& disc)
{
int32_t track = disc.GetFirstDataTrack();
if(track < 0) {
return false;
}

int32_t sector = disc.GetTrackFirstSector(track);
if(sector < 0) {
return false;
}

//Check for custom homebrew marker to automatically enable SuperGrafx mode for CD games
//This should be in the 2nd sector of the first data track, at offset 0x80
vector<uint8_t> sectorData;
disc.ReadDataSector(sector + 1, sectorData);
return memcmp(sectorData.data() + 0x80, "(for SuperGRAFX)", 16) == 0;
}

bool PceConsole::IsSuperGrafxCard(uint32_t crc32)
{
//These are the 5 SuperGrafx-exclusive games
Expand Down
1 change: 1 addition & 0 deletions Core/PCE/PceConsole.h
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Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,7 @@ class PceConsole final : public IConsole
RomFormat _romFormat = RomFormat::Pce;

static bool IsPopulousCard(uint32_t crc32);
static bool IsSuperGrafxCd(DiscInfo& disc);
static bool IsSuperGrafxCard(uint32_t crc32);

bool LoadHesFile(VirtualFile& hesFile);
Expand Down
11 changes: 11 additions & 0 deletions Core/Shared/CdReader.h
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Original file line number Diff line number Diff line change
Expand Up @@ -96,6 +96,16 @@ struct DiscInfo
return -1;
}

int32_t GetFirstDataTrack()
{
for(size_t i = 0; i < Tracks.size(); i++) {
if(Tracks[i].Format != TrackFormat::Audio) {
return (int32_t)i;
}
}
return -1;
}

int32_t GetTrackFirstSector(int32_t track)
{
if(track < Tracks.size()) {
Expand Down Expand Up @@ -135,6 +145,7 @@ struct DiscInfo
uint32_t byteOffset = trk.FileOffset + (sector - trk.FirstSector) * sectorSize;
if(!Files[trk.FileIndex].ReadChunk(outData, byteOffset + sectorHeaderSize, 2048)) {
LogDebug("Invalid read offsets");
outData.insert(outData.end(), 2048, 0);
}
}
}
Expand Down