It appears that the C-BIOS package in Debian only ships the most recent C-BIOS files. I think we can't just depend on it for this reason, since the older C-BIOS ROMs are needed to avoid save state breakage. See Contrib/cbios-old/README in the openMSX package.
-- Aaron Rainbolt Lubuntu Developer Matrix: @arraybolt3:matrix.org IRC: arraybolt3 on irc.libera.chat GitHub:https://github.com/ArrayBolt3