Compact QBus Systems (Was re: Los Angeles: Commodore PET 8032's...)

From: John Wilson <wilson_at_dbit.dbit.com>
Date: Sun Mar 12 11:50:42 2000

On Sun, Mar 12, 2000 at 08:14:19AM -0500, Daniel T. Burrows wrote:
> >What I'm really hoping for is what was I think called a BA23-SE or BA11-SE,
> >'twas a desktop 4-slot enclosure, maybe even 4x2?
>
>
> I think what you are looking for is the BA11-MA. Desktop 4 slot Qbus the
> same approx. size as a dual TU58.

I thought that was the BA11-VA? That's what mine say on them anyway,
and yeah they look very much like a TU58, but with a 4x2 18-bit backplane.
Easily wire-wrapped to 22 bits, and I hung a piece of perf board with a PIC
CPU off of the BEVNT line on one of mine to count a 32 kHz watch xtal down
to 60 Hz (since the PSU doesn't drive BEVNT in this box), so that it could
boot RSX and RSTS from a Zip drive. All because I couldn't remember what
the old chip was that could divide a colorburst xtal down to 60 Hz, Allison
has since told me it was the NS5363. *Very* practical box for a PDP-11,
it's smaller than a PC even...

John Wilson
D Bit
Received on Sun Mar 12 2000 - 11:50:42 GMT