[Coco] RGB-DOS ROM identification

[Robert Gault]

Bob Devries wrote:
> Hi gang,
> I have in my hardware collection an FD502 (26-3133) controller that has 
> an EPROM in it that has a label with RGB-DOS $0188DC on it.
> 
> How can I identify what kind of hard drive this was used with?
> 
> -- 
> Regards, Bob Devries, Dalby, Queensland, Australia

The label is cryptic but the number just might be the size of the hard drive in sectors or 
  the size of the OS-9 section in sectors.

PEEK the bytes $D938 (MSB) and $D939 (LSB) to get (if present) the offset in 256 byte 
sectors to the start of the Disk Basic section of the hard drive. If the value is 
$00000000, then the drive was used only for OS-9.

The only way to get more information on the type of drive used with this ROM will require 
disassembly of the code to see what command codes were used. That might suggest the type 
of drive in the system the ROM controlled.