There are 5 repositories under pc9801 topic.
Notes relating to using PC9801/9821 (and possibly other retro PC system) disks in Linux
PS/2 - pc-98 bus mouse converter using Arduino compatible board
PS/2 (AT) to PC-98 keyboard converter
Mirrored source code of Professional Music Driver (PMD) parts, publicized by Masahiro Kajihara (includes a cuatom gitignore)
A Russian translation of the PC-98 game Aegean Kai No Shizuku by Illusion Core.
An English translation of the PC-98 game Aegean Kai No Shizuku by Illusion Core.
🗂️ Java filesystem SPI over jnode (ntfs, ext2, fat, pc98, etc...)