Which Dec Emulation is the MOST useful and Versatile?

Rob Jarratt robert.jarratt at ntlworld.com
Tue Oct 24 12:42:42 CDT 2017



> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Dave Wade
> via cctalk
> Sent: 24 October 2017 10:01
> To: 'Kip Koon' <computerdoc at sc.rr.com>; 'General Discussion: On-Topic and
> Off-Topic Posts' <cctalk at classiccmp.org>
> Subject: RE: Which Dec Emulation is the MOST useful and Versatile?
> 
> Kip,
>  It depends on what your interest is! Of course PDP stood for "Programmed
> Data Processor"
> 
> https://en.wikipedia.org/wiki/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.
> 

Ah the PDP10! Although the very first computer I used was a PDP11, it was so
briefly that I really consider the PDP10 (in DECSYSTEM-20 form) to be my
first computer. It is easy to emulate in SIMH, although the SIMH emulation
is of a less capable processor (KS10) and I think KLH10 is the best emulator
for that (but I have never used it).

For general DEC goodness I would go for a PDP11 or a VAX, preferably both.
And as Dave and others have pointed out, PDP was not really a line of
computers, it was multiple lines of different computers.

I forsee a *long* thread here.

Regards

Rob



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