Allows the BBC Micro to read ISO-9660 formatted CD-ROMs, and control certain other drive functions, with an IDE CD-ROM drive attached to a 16-bit IDE interface as described by J.G.Harston.

cc65 is required to build- type make and you should get cdfs.rom.

• I've mostly implemented OSWORD &24-&27 to interface with ATAPI devices, similarly to VFS's &60-&63 and ADFS's &70-&73.
• The filing system layer is not working yet.
• There are some optional test commands assuming a controller at &FC40 with a CD-ROM drive in the slave position, which I have considered as drive 1 on the BBC.
• I'm developing this with BeebEm (with host IDE passthrough) on VMware Fusion on an Intel Mac.
• It uses zero page locations that it shouldn't, so may not coexist with some applications or languages other than BASIC. (See also bbctestrom. Ideas on fixing this while using cc65 may be welcome.)
• It needs to be loaded into writable sideways RAM, not an actual ROM.