@IPXFong @leadedsolder yeah if you see no video it's normal, it only loads video if it boots.

@IPXFong @goosey @leadedsolder If the drive is "known" to work, there's using a greaseweazle but given it's only one drive it should be easy to replace (also interesting yours looks like it has a HDD, I'm curious what kind it uses).

@IPXFong @goosey @leadedsolder Also notable is that the expansion bus is physically identical (no idea if electrically) to the PC-9801's expansion bus, C-Bus. The BIOS is definitely not the same even if it's a close relative, given it lacks N88-BASIC(86). Unlike the APC III, the 9801 had tons of expansion cards including a PC-FX on a board, GPIB boards, and many sound/video cards.

https://ja.wikipedia.org/wiki/C%E3%83%90%E3%82%B9

These pins are also directly wired to the PSU pins.

So I'm sharing this here for visibility, but the #i915 #Intel #Linux driver on Broadwell systems has a bug where the system will sometimes freeze up for a few seconds when opening 3d programs including web browsers. This can be triggered by running Furmark over and over.

https://gitlab.freedesktop.org/drm/intel/-/issues/10091

@IPXFong @goosey @leadedsolder You're welcome, and also as for the video it uses ttl/digital RGB out of the 9 pin port, but it's 24khz. This is because the PC-9801 is 24khz.

Also importantly, remove the NiCD battery. It leaked on mine and now the motherboard needs some work as the video RAM is having issues. One of the APC III disks is a test disk to make sure the hardware works along with the official upgrades.

@IPXFong @goosey Here's the DOS floppies; these work with a Gotek (use shugart mode, also the drive IDs are set via the drive itself):
https://archive.org/details/nec-apc-apc-iii-n-5200-images.-7z

If you want info/help on making the APC III working, there's two good Discord servers I'd recommend, the PC-9801 Central and @leadedsolder 's server. He messes with weird Japanese computers all the time.

https://discord.gg/gurn9zh2zE
https://discord.gg/aaAyFzpu

@IPXFong @goosey
Hi there, I have no idea if this post will go through but I'll try. I am also a proud APC III owner.

It's very similar to the NEC PC-9801F, with one big difference: no BASIC/font ROMs, and the floppy disks are 360k and not 80 track like on the 9801F. The software is on archive.org. If you get a black screen, that's normal, the old PC-98 BIOS does not display text until the system boots DOS. It also will only attempt to read disks with the head down.