Which Dec Emulation is the MOST useful and Versatile?

Dave Wade dave.g4ugm at gmail.com
Tue Oct 24 04:00:34 CDT 2017

 It depends on what your interest is! Of course PDP stood for "Programmed
Data Processor"  


and avoids the use of the word computer because the backers of Digital did
not want them building a Computer. I believed it also helped sales as it
by-passed corporate purchasing edicts which said only central IT departments
could buy computers...

The PDP8 is the smallest but most hackable, but things like Oscars 8I or the
SBC6120 which turns up from time to time (google SBC6120) mean that its
possible to have something approaching a physical PDP-8 to play with rather
than just emulation. But if small is beautiful then may be the machine for
you. These were used all over the place. Manchester University Medical
School had one connected to its IBM7090, Leeds to its KDF9. Really a
revolution in computing. Its amazing what folks got to run on these using
only paper tape. Eventually made in a Microprocessor with the Harris and
Interrail 6100 and then the Harris HD6120..

 The PDP-11 covers a huge range of systems and I know there are still some
PDP-11's in service. At one time Barclays, a UK bank used them as Branch
Controllers so every branch had a PDP-11 and in those days there were many
more branches than there are now. I learnt BASIC on one at Salford
University in 1977. When I worked for the uk's Natural Environment Research
Council we must have had hundreds of the things. We used them to build
"media conversion" systems that would copy data from scientific instruments
and to build front end concentrators for our Honeywell L66. More capable
than the PDP-11 but possibly less easy to hack. Lots of different Operating
Systems out there but for some licensing is interesting.  Was used to
develop early Unix

 The VAX-11 is probably my favourite box. I have several physical VAXen all
with the VMS OS installed. Really gives a flavour of what interactive
computing was like in the 1970's and 1980's. Very capable but even less easy
to hack, and initially big and expensive, which is why the PDP-11 continued
to be available for many years.

 There is also the PDP-10/Dec System 10 which was claimed to be a Mainframe
but I never met one of these. Probably not for the faint hearted.


> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Kip Koon
> via cctalk
> Sent: 24 October 2017 06:46
> To: cctech <cctech at classiccmp.org>
> Subject: Which Dec Emulation is the MOST useful and Versatile?
> Hi DEC Enthusiast's,
> If I were to have to decide on just one model DEC PDP system to run in a
> Emulator, which one would be the most useful, versatile and has the most
> software available for it?
> I have only ever used a real PDP-8/e system way back in high school so I'm
> not up to par on any other model of DEC PDP system and I only know BASIC
> on the PDP-8/e so not much there either.
> I hear a lot about the PDP-11.  I found out that there were 16 major PDP
> models at one time so I'm not too sure which one to pick.
> I built Oscar Vermeulen's PiDP-8/I which I'm waiting on 1 part for.  Other
> that project which is in a holding pattern at the moment, I have no other
> anything running in any form.
> Back in the day when Bill Gates and company 1st started out, I had always
> wondered how they developed their very 1st software program - Altair
> I was pleasantly surprised one day when I saw a B/W photo of a young Bill
> Gates bending over the operator at what looked like a very small computer.
> Maybe it was just a terminal.  I don't remember.  I understand they did
> software development on a DEC PDP of some sort.
> Finding this out regenerated my interest in the DEC PDP line of computers.
> I have many projects in the works already so I decided to setup a software
> emulation of just one of the DEC PDP models.  I have heard a lot about the
> PDP-11 which if the information I read is correct was 16-bits.  My
PiDP-8/I is
> 12 bits.  I understand the PDP 10 was 36-bits and the PDP-15 was 18-bit.
> The PDP-11 is the model I hear the most about.
> I also have some experience on some version of  a VAX when I was in the
> Force so I'm thinking of getting a VAX emulation going at some point too.
> So if I'm going to do this, what suggestions, pointers, experiences,
> do you guys have for me.  I am very interested in the DEC PDP equipment
> though next to no experience so I have no basis to make a decision.  This
is a
> serious request so I would definitely like to hear what you all have to
say.  If
> you have read this far, thank you.  Take care my friends.
> Kip Koon
> computerdoc at sc.rr.com
> http://www.cocopedia.com/wiki/index.php/User:Computerdoc

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