1 Mar
2008
1 Mar
'08
4:35 a.m.
Subject: Re: Qbus to CF / IDE
From: Doc Shipley <doc at mdrconsult.com>
Date: Fri, 29 Feb 2008 19:09:12 -0600
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at
classiccmp.org>
tiggerlasv at aim.com wrote:
Forgive me if this is a silly question, but is 10MB a limitation of
the firmware and drivers, or of the disk technology?
None of the above. There is a limit of 32mb for RT11 disks because
because the sector pointer is only 16bits and sector size is 512bytes
(65536*512=32mb).
The real problem is few people know how to write a driver and if they
do it's only for one OS and the list of OSs [UnixVn, RT11, RSTS,
RSX11, VMS, Ultrix, other?] means a driver for each. Once you have
a working driver a booter is possible.
The RL driver cant be used as it's dependent on DMA and a simple IDE
interface will not likely include that. So the model for the driver
is more likely DD[tu58], DX [rx01], DY[rx02] or maybe some other but
with the dimension table altered as they used PIO for the transfer.
Allison
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.
Doc
--m21CTBEw048667.1204374551/keith.ezwind.net--