Microvax II

From: Jerome Fine <jhfine_at_idirect.com>
Date: Fri Oct 13 21:29:23 2000

>Neil Cherry wrote:

> BTW is it easy to design boards for the Microvax. This Analog board seems
> really simple. Designing an intelligent SCSI board wouldn't be a lot more
> difficult (I didn't say anything about the Vax driver).

Jerome Fine replies:

I doubt very much that the answer is YES! Otherwise, it would have been
easy to produce the 3rd party SCSI host adapters and there would have
been a lot more competition - even with the $ US 100 license fee.

Now I have heard of someone attempting to produce a Qbus controller
for an IDE drive that would not even be MSCP - and probably put the
IDE drive right on the controller - not that MSCP would be all that
difficult in any case, but the primary objective was to keep the price
as low as possible and avoid the $ US 100 license fee from DEC.
The device would have looked like a very simple register driven
hard disk drive that already has a device driver for one of the OSs
in the PDP-11, not that a device driver for VMS could not also be
produced in that case. I am not sure why it was never completed,
but if it was that simple, I am sure it would have been done.

There have been a large number of 3rd party Qbus boards from a few
companies in the past. Did DEC discourage them - probably. Was
it easy to design the boards. More than likely, but maybe the cost
of fabrication was high or the volume too low. Hard to know why
most - I think I know of just one left - are no longer in business
producing Qbus boards. Of course, DEC was no longer producing
many Qbus boards even before it became Qed. But there is
still a thriving trade in old Qbus boards. I imagine that if it was
so easy to produce them new, that some small company would
come along and do so. After all, cars have knock off parts. But
maybe, again, the volume is just too low.

Sincerely yours,

Jerome Fine
Received on Fri Oct 13 2000 - 21:29:23 BST