Qbus to CF / IDE

Patrick Finnegan pat at computer-refuge.org
Fri Feb 29 19:51:10 CST 2008

On Friday 29 February 2008, Doc Shipley wrote:
> tiggerlasv at aim.com wrote:
> >>  You could have, for example, four RL02s each capable of being
> >>  assigned a "pack" from the card.
> >>
> >>  What were the biggest non-MSCP-attached drives?
> >>  How hard would they be to emulate?
> >
> > While RL02's would probably be easy to emulate,
> > at 10MB a pop, you don't get alot of bang for your buck.
>    Forgive me if this is a silly question, but is 10MB a limitation
> of the firmware and drivers, or of the disk technology?

Well, RL02s are 10MB.  There's no reason that you couldn't have 
something on the same interface with more tracks (the only real 
difference between the RL01 and RL02 were the number (and thus width) 
of tracks on a cartridge).

The biggest problem would just be that the appropriate drivers wouldn't 
expect to see anything other than an 5MB or 10MB disk.  It probably 
wouldn't be too hard to patch the drivers for a larger (fixed) size, 
but I think most people just want a "drop in place with existing 
software & drivers" solution.

I'll note that there were third-party controllers which took a cheap 
ST506-like (or whatever) disk and emulated multiple RL02s to the host.  
Actually, I think that's pretty much what the DSD880 (which I have one 
of) does.  However, it's probably a whole lot less useful to emulate a 
bunch of tiny disks than one big disk, at least for most people.  Now, 
if there were only software RAID drivers for RT-11 et al, you could 
combine those back into one big disk. :)

Purdue University Research Computing ---  http://www.rcac.purdue.edu/
The Computer Refuge                  ---  http://computer-refuge.org

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