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

From: Eliot Moore <elmo_at_mminternet.com>
Date: Sun Mar 12 02:03:39 2000

Jerome Fine wrote:

> Jerome Fine replies:
>
> Be careful if you are considering a VT103. The original DEC backplane
> was only 18 bits (only 256 KByte of memory) although if you are handy
> with a soldering iron, the extra wires can be added to make it 22 bits.
>
> ALSO, the unit is VERY under powered. The DEC specs say only 16 amps
> on the 5 volts which also includes the video interface and the AVO option
> if you want a full screen 132 character display. I suggest that if you use
> a Quad 11/73 with the RQDX3, you are probably OK. But not much else.

I no longer need 132 columns to be fulfilled, so the AVO can be omitted.

I'd be attempting a dual 11/73, NS 256Kb, Sigma DLV11, and CMD 220 TM SCSI. If
that doesn't work, I'll try taking out the DL and memory and using an MXV11,
though I recall those only have 32Kb or 128kb, which would make it pretty
difficult to run RSTS/E.

> Put any hard drives on an external PC power supply.

Good advice for _any_ qbus system. I learned that the hard way, running 4-5
SCSI devices (2 sets mirrored) in a BA23 chassis, and wondering about the
mysterious lockups. External drive chassis eliminated those, though cable
lengths became very critical.

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?

Regards,
Eliot
Received on Sun Mar 12 2000 - 02:03:39 GMT