old processor architectures [was Re: The Strange Birth and Long Life of Unix - IEEE Spectrum]

[James Knott]

phiscock-g851W1bGYuGnS0EtXVNi6w at public.gmane.org wrote:
> To mention an example of what the PDP-8 was capable of: Back in the early
> 70's Durham College had a PDP-8S, which used a serial ALU
> (arithmetic-logic unit), ie, one bit processed at a time. (I think the
> register transfers were all serial as well. In those days, hardware was
> *expensive*.) They had a 64K hard drive attached to the computer. The
> drive was enormous - it just barely fit into a 19 inch rack and sounded
> like a washing machine on spin cycle.
>
> This computing facility ran a timesharing computing service of 4 ASR-33
> teletypes, supporting the FOCAL programming language, which was an
> interpreted language something like BASIC. It was pretty slow when you got
> four people on the terminals and man, there was a lot of activity in the
> carry-bit indicator. But it did work.
>
> Of course, time-sharing is fairly trivial using an interpreted language,
> but it was still pretty impressive in the day.

At work, we had one PDP-8i and also several Nova 800s across the 
country.  I don't recall the disk size on the PDP-8 (16K?), but it was 
much smaller than the Novas which had either 128 or 256K.  They both 
used head per track disks.  Both systems were connected to several 
terminals used to enter telegrams at CN Telecommunications/CNCP.
>
> Personally, I found programming in PDP-8 assembler a huge chore and never
> got the hang of it. The 6502 instruction set was a gift from god by
> comparison.
>
>
Other than a FORTRAN class in high school, my first programming 
experience was on the Datapoint 2200 terminal, which used the 8008 
instruction set.  The Intel 8008 was originally intended for that 
terminal, but it wasn't fast enough, so Datapoint went with discrete 
logic to build their CPU.  About a year later, I bought my IMSAI 8080, 
which had the 8080 CPU, which was much better than the 8008.  Another 
year later, I was working with the Nova 800 and found it's instruction 
set to be primitive compared to the 8080.

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