Now that the PC98 can load a game off a flash drive, there’s a lot more parts of it I can test. Today, I spent a few minutes putting together a new revision of the floppy board and inspecting the computer.

New floppy board

I changed the Molex connector’s footprint in KiCad and re-spun the board, and also moved the Molex to the other side of the board. Now, we can panel-mount this nice Molex connector, in order to provide power to the Gotek floppy drive.

Floppy adapter with better power footprint

I’m getting pretty good at putting these things together by now, if I may say so myself.

New PC98 floppy board assembled

Unfortunately, after I put the board together and plugged it into the computer, I realized it was quite the tight fit. Not all of my Molex-to-Berg adapter cables were able to do such a small-radius bend, and it would be impossible to mount the drive in the top bay like this. Luckily, I don’t plan to, but there’s some work that could be done in future revisions of this board.

New PC98 floppy board has an awkward angle on the connector cable

I didn’t run into the weird freezing behaviour described in the previous entry since the initial fire-up. My best guess is that it was something to do with the FlashFloppy firmware’s first run; creating a config file or something along those lines. Everything runs great without me having to toggle any front-panel buttons to force it to work.

A few more holes of Marvel PuttGolf - I really should get a new game on this flash drive - and it was time to hit the next problem on my list.

The mouse

I had a mouse, but nothing to test it with. It turns out Marvel PuttGolf lets you use the mouse, so I plugged it in and gave it a shot.

The mouse works, or at least the movement and left button does. Clicking the right mouse button seems to do nothing, but it’s more likely that the game doesn’t do anything with that button.

It’s really hard to play this game with a mouse. Keyboard (or joystick) only for me.

Fixing the sound

The auction seller stated that the machine didn’t make the expected “pipo” beep, and when I received the machine a few months ago, I found out at least one of the reasons why. After opening the machine, I realized that the internal speaker had been unplugged.

Speaker plug is unplugged

Maybe it was just disabled in the BIOS? It wasn’t, and even though the battery isn’t in great condition, the default NEC BIOS configuration appears to be set to “sound on, all the time.”

I looked at the board to see if any of the caps were bad and found this corrosion, which another PC9821AP2/U8W owner had complained about on another message board. It looks like the adhesive or something goes acidic and corrodes out part of the board. I am surprised the traces are okay! Definitely need to get back in here and clean it up with alcohol and vinegar to see if I can keep it at bay.

Odd corrosion

Thinking the speaker might have been unplugged because it didn’t work, I plugged in an external speaker to the audio jack on the front of the machine. Still no sound!

Just as I was about to give up, I looked at the removed front panel again. There are volume dials on the front for both speaker volume and microphone volume, and somehow during my previous testing I had turned the speaker volume all the way down.

I turned it back up, and was rewarded on the next boot with a confident PIPO!

Now we can enjoy some classic FM freeware music:

Not sure why it keeps changing instruments and pitch - I’m not a musician, but that feels like an odd choice to make deliberately - but FM synth seems to be working. On to the next challenge!