My PC-98 doesn't run anything except for Rude Breaker - noob question

Started by lucaspam, February 22, 2023, 11:30:25 AM

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Hello There Everyone,

I've just picked up a PC 9821-V12, with almost 50MB of RAM and a soundcard that is identified as a YM-2203.

The computer came with an CF to IDE board, a 4GB card and I am assuming that a version of YAHDI (yet another hard disk image) is already installed on the CF.

The problem is, from the list of games that came already installed, only Rude Breaker seems to work fine. The other games crash and burn heavily upon loading. Rusty works roughly 30% of the all the times I've tried and stops working soon enough into the first stage. Flame Zapper doesn't produce any sound and Garudius is just a blurred mess on the screen - other games just run too fast.

The BIOS doesn't feature the option to lower CPU speed. Some games run very fast, then stop working with a terrible sound from the soundboard. I believe the CPU is just too fast. Is there any way to slow down the CPU? Some command perhaps?

I know this is a noob question, but I've searched the forum and found no user with a similar issue. Any help is appreciated. Thank you dearly for your attention! 


That game is so great Im not sure you need to run anything else :P. Id love to play a rude breaker machine again!

Why is your CPU too fast?  Was it overclocked?  Corrupted sprites and out of pitch sound are def symptoms of overclocking which a lot of people did back in the day.  there might be a hardware mod to remove somewhere.
I design PCBs for retro game systems :)


Thanks for answering, Segasonicfan! I haven't disassembled my pc-98 entirely - maybe i should do it for inspection. The CPU is a Pentium, though, and most of the games are made for the 486, including Rusty, I think. I am observing exactly what you are describing, sound out of pitch, garbled graphics, sometimes the games fail to execute.

Maybe the problem is with my HDD image? do you know any other HDD image that is made for proper use with a newer PC-98?

thanks again for your answer!


I would imagine by the 486 era games would've been made to run fine on faster hardware just fine.
PC games of the era certainly were, but you never know with PC98.

The fact that one game runs fine is puzzling though. I haven't seen any HDD images designed around fast PC98 machines.

Another factor is that the later PC98 revisions were increasingly more PC-like and broke hardware compatibility with games.

I think that is why most people want the cs2 revision as it was right in the sweet spot. Maybe your machine is just too late a revision?


Have you tried messing with the GDC clock setting? That's going to be in the BIOS and is not related to CPU speed.

Sound problems could be due to the onboard sound not being completely disabled or the game not being configured properly.


Yeah, not setting GDC clock correctly will break most games. This is prolly what is the issue here. It is one of those obscure details that trips most newcomers.


Hello there people!

Thanks for all your replies. I believe I already tried this GDC clock setting on the BIOS. I think there were two options: 2,5 or 5. I do remember that Rusty refused to load with the 2,5 option. I will try again and will return here.

Thanks again for all your attention!