PDP-11/53+ Jumpers

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Wed Jun 6 18:34:50 2001

I have a 11/73 and several 11/23s (some with clock mods for speed)
so I'm aware of what I said. MOST early 11/53 boxen actually had 11/23B
cpu cards (M8189).

Oh yes, I do have a very fast 11/23B as a result of a modded clock.

Allison


-----Original Message-----
From: Jonathan Engdahl <engdahl_at_cle.ab.com>
To: classiccmp_at_classiccmp.org <classiccmp_at_classiccmp.org>
Date: Wednesday, June 06, 2001 2:45 PM
Subject: RE: PDP-11/53+ Jumpers


>The M7554 has a Qbus on the A-B connector, and nothing but grant jumpers
and
>power on the C-D connector.
>
>I don't know anything about 11/73's, but the first thing I noticed when
I
>got the 11/53 to boot was "Whoa! -- this thing is a lot faster than an
>11/23".
>
>Maybe Allison had better go looking for someone with a very fast "11/23"
and
>get his CPU board back!
>
>--
>Jonathan Engdahl Rockwell Automation
>Principal Research Engineer 24800 Tungsten Road
>Advanced Technology Euclid, OH 44117, USA
>Euclid Labs engdahl_at_cle.ab.com 216-266-6409
>
>
>> -----Original Message-----
>> From: owner-classiccmp_at_classiccmp.org
>> [mailto:owner-classiccmp_at_classiccmp.org]On Behalf Of Pete Turnbull
>> Sent: Wednesday, June 06, 2001 3:22 AM
>> To: classiccmp
>> Subject: Re: PDP-11/53+ Jumpers
>>
>>
>> On Jun 5, 22:37, ajp166 wrote:
>> > Isn't the 11/53 the box name and the cpu being either an 11/73
>> > or 11/23B? All the 11/53s I've seen had 11/23B cpus (M8189).
>>
>> No, an 11/53 processor is an M7554, which is a quad board with J11,
half a
>> meg of memory, 2 SLUs, bootstrap, etc. It's rather like an
>> 11/73B but with
>> added memory (and no PMI capability, I think). It was designed as a
low
>> end system, and IIRC it's slightly slower than an 11/73.
>>
>> If you saw 11/53 BA23's with 11/23's in them, someone swapped the
>> cards, or
>> swapped the labels.
>>
>>
>>
>> --
>> Pete Peter Turnbull
>> Network Manager
>> University of York
>>
>
Received on Wed Jun 06 2001 - 18:34:50 BST