[Coco] The DOSes

[Robert Gault]

Joe Grubbs wrote:
> Pardon my ignorance on the subject of CoCo DOS and really anything Disk oriented. My original CoCo never received the gift of non-cassette storage, and now as an adult the CoCoSDC is my first exposure to anything other than cassette.
>
> I know that Disk Extended Color Basic is ECB with Disk I/O commands implemented by the ROM inside the FD50x controller
> SDC-DOS seems to be a similar concept, though specific to the CoCoSDC
> I gather that HDB-DOS is again similar, only it is specific to the DriveWire client? (correct me if I'm wrong).
>
> What is RS-DOS? And are there other common DOSes in use by the CoCo community?
>
>
>   		 	   		
>

HDB-DOS is based on the patched Disk1.1 ROM that came with the Ken-Ton hard 
drive system. Cloud-9 bought the rights to RGB Computer Systems software 
(RGBDOS) and created HDB-DOS. Prior to that, I as an owner of a Ken-Ton hard 
drive system, created a version of RGBDOS for emulators where I replaced the 
SCSI commands with those required by emulators. RGBDOS is incorporated in VCC, 
and can be used with the JVC and MESS emulators.

RGBDOS, as supplied with the Ken-Ton hard drive system, had versions for several 
different types of hard drives. HDB-DOS continues and expands on this so that it 
now handles Drivewire, IDE, SASI, and SCSI hard drives. I think it also works 
with CDROM drives.

RGBDOS/HDBDOS is backwards compatible with Disk Basic 1.1 (with some 
enhancements) but is particularly useful with real or emulated hard drives where 
the hard drive can be split into two partitions, one for OS-9 the other for Disk 
Basic. In the Disk Basic partition, you can have 256, 35-track Basic drives. 
I've a paper on the Cloud-9 site showing how you can increase the number of 
Basic drives by changing the partition offset values.
When RGBDOS was created, hard drives were small. My Tandon TM252 drive has 32760 
sectors assigned to OS-9 leaving only 11, 35-track, 256-byte sector drives for 
Disk Basic.

Robert