Valis: The Legend of a Fantasm Soldier — incorrect BIOS auto-detection causes CDDA desynchronization #168
Description
Activity
- locked and limited conversation to collaborators
on Aug 24, 2026 - unlocked this conversation
on Aug 24, 2026 Please provide:
- Geargrafx version and whether you are using the desktop app or RetroArch/libretro
- The exact BIOS file(s) used (name and MD5), since Geargrafx does not ship or use separate "US" and "J" region BIOS files — only System Card 1/2/3 and Game Express are supported
- Platform: Windows, macOS, Linux, etc.
- The exact CD image title, region, and hash tested, plus the non-default BIOS setting used
This is an automated triage request generated by Issue Triage
Are you using Geargrafx in RetroArch?
Geargrafx does not have an "Auto" mode for bios in desktop.
In RetroArch it selects from
syscard1.pce,syscard2.pce,syscard3.pcebut it can't tell the difference between US and JAP bios. But we can convert this into a feature.Tested with
syscard3.pceandsyscard3u.pceand I can't tell any difference.From their automated report, OP seems to only use one syscard.
As Dr. Helius said, there is no auto BIOS selection, only auto "region" (auto system actually).I checked all system combinations possible (except SuperGrafx):
- syscard3j + PC Engine
- syscard3j + TurboGrafx
- syscard3u + PC Engine
- syscard3u + TurboGrafx
In all cases, the intro is perfectly synchronized with the audio.
The only strange bug I met with the syscard3u is that the Japanese logo "Nihon Telenet" at the beginning of the intro is cut in half, but it might happen on the original hardware. I'll check later with other emulators and my TED Pro.
Thanks @Ryusennin
For info, I just checked with Mesen + syscard3u and the same cut-off logo bug happens as well. I suppose it's another one of those quirks between Japanese games and the US Super CD-ROM.
Does it make any sense having an "Auto" option for bios?
I think the existing "Auto" option in libretro code is confusing. It should work only for choosing syscard vs gameexpress.
Regarding the original desync of the OP, maybe tested with an old version of the core and not really latest. Providing actual version is always better.
On the real hardware, there are a handful of known bugs happening when running Japanese SCD games with a US syscard. To my knowledge, all US games work properly with a JP syscard. Maybe an auto BIOS feature to force JP syscard with JP games would be warranted.
Really, the only interest of the US BIOS is the translated BRAM manager menu.
Reacted by Nacho Sanchez GinesRemoved "Auto" from libretro bios option.
Made the description a bit less confusing.Super CD-ROM System [3.0] (J)is always recommended.@Ryusennin me too the logo is trucated
Indeed it seems Us bios can apparently boot jp game, on the original hardware but in that case for sure the audio is wrong!
As it's on the real hardware no possible fix except warn people to use the exact region card somewhere! Furthermore as i already did this game on magic engine, i remembered the same, issue, but no auto region so, i thought as there was auto, that it detect the region, but did not switch to jp bios!Regarding info sorry for the delay: latest geargrafx, et linux, for the rest it's unnecessary it isn't both a bios issue, nor a file issue.
Just difficult to remember that card must manually match the game!
Perhaps the good way is to correct the original issue (forbid launching non matched bios game) then ad auto region select...
It's annoying as we re in virtual, user may first incriminate the emu, all the time...For the synchro check it's relatively easy, she start to speak after some time, and there if Us bios delay, and with jp bios ok
Sorry but "latest geargrafx" does not say anything to me.
Can you share the exact version where you noticed the audio desync?1.7.18, but again it's the true behavior, i recall now that 10 years ago magic engine did the same thing on this game!
Reacted by Nacho Sanchez Gines
Generated via AI:
Environment
Emulator: Geargrafx latest
OS: Lubuntu Linux 26.04
System: x86_64
Hardware: Intel Core i7-3840QM / Intel HD Graphics 4000
Game
Title: Valis: The Legend of a Fantasm Soldier
System: NEC PC Engine CD / Super CD-ROM²
Region: NTSC-J (Japan)
Media: CD image
Description:
Geargrafx's automatic BIOS detection appears to select the wrong BIOS for this Japanese PC Engine CD game.
When BIOS selection is left on automatic, the game appears to be launched using the US BIOS instead of the Japanese BIOS (J).
This results in incorrect CDDA synchronization during the game's cinematics.
Steps to reproduce
Launch on Lubuntu Linux.
Load the Japanese CD image of Valis: The Legend of a Fantasm Soldier.
Select us bios.
Start the game and observe the cinematics and CDDA audio.
Repeat the test with BIOS J explicitly forced.
Actual behavior
With BIOS US:
The Japanese game is apparently assigned the US BIOS.
CDDA audio is approximately 1 second out of synchronization with the video during the cinematics.
Anyway it should have never launch.
With BIOS J forced manually:
The same CD image is correctly synchronized.
The CDDA/audio and video are synchronized.
Expected behavior in case of bios auto detection:
Geargrafx should detect the NTSC-J / Japanese region of the game and automatically select the appropriate Japanese BIOS (J).
The user should not have to manually force BIOS J to obtain correct CDDA synchronization.
Conclusion
This appears to be a BIOS auto-detection / region detection bug.
The decisive observation is that the exact same Japanese CD image produces incorrect CDDA synchronization when BIOS selection is automatic, while forcing BIOS J immediately restores correct synchronization.
Therefore, the problem appears to be related to the BIOS selected by Geargrafx's automatic detection rather than to the CD image itself.
Workaround
Manually force BIOS J before launching the game.