This subdirectory should contain the following ROMs:
- nms8250_disk.rom, nms8250_basic-bios2.rom, nms8250_msx2sub.rom: same as
  needed for the Philips NMS 8250 config
- fmpac.rom: same as needed for the FMPAC extension
- yrw801.rom: same as needed for the Moonsound extension
