Vt 103 / lsi 11/23 marketed as a desktop late 1980

Ethan Dicks ethan.dicks at gmail.com
Thu Apr 21 21:31:49 CDT 2016

On Thu, Apr 21, 2016 at 9:41 PM, Jerome H. Fine <jhfinedp3k at compsys.to> wrote:
>>william degnan wrote:
>> Prior to the DEC Rainbow, Chrislin Industries was marketing the 11/23 with
>> vt103 as a  desktop computer.  This is a 3rd party vendor.  Maybe they
>> were on to something...
> Back around 1988, one of my customers had a few VT103
> systems with just an RX02 for storage.  A 3rd party
> controller for an MFM drive (ST506 or DEC RD51) was
> added since the DEC RQDX1 took too much power.  There
> was still sufficient power and room to place the
> ST506 drive inside at the base of the VT103.

Sounds like a sweet little system... in 1987, I was using an 11/23 in
a BA11N (5.25"-tall rack-mount box) with RX02 and RLV11+RL01, so
packing all that, including the 5MB disk into a VT103 would have been
quite nice.

> Prior to that point, I had a VT103 with just 256 KB
> of memory and a DSD 880/8 which had an 8 GB hard
> drive / RX03 floppy drive in an external box.  So
> there were other 3rd party solutions as well.

8MB?  But otherwise, also nice.

> At one point, just to say that I had done so, I placed
> a quad PDP-11/73 CPU along with 4 MB of memory, an ESDI
> controller and a DHV11 with 8 serial ports into the
> backplane of a VT103.

Now you're talking!

> I had to power the three 600 MG
> hard drives from an additional PC power supply since
> there was insufficient power from the VT103.


>  But that
> demonstrated that just a 4 x 4 Qbus backplane was
> sufficient to run an extremely powerful PDP-11 system
> using the VT103 as a base system with its own console
> terminal.

Yep.  The biggest limitation was power, the second was limited number
of slots, so you needed small but powerful cards to make it

> At one point, I heard that someone even
> managed to make the first two slots ABCD which allowed
> a MicroVAX II to be used instead

Wow.  That sounds like a fun but much bigger hack.

I have a VT103 (w/TU58)... I did set up a simple 11/23 in it once, but
I should see what I can do with a SCSI card...


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