I assert it was an 8 bit machine. We used a PDP-4 with 4K of static ram (which was toroids wired appropriately). I believe that the US Coast Guard was the first group to take a PDP-4 to sea on the CGC Evergreen, and used it to process oceanographic data. Then about two years later came the 8-S, which you could carry under your arm with 8 K of static ram. No installation was required- clear the desk space and plug it in. This was really the machine that started things going. PAL was the programming assembly language that one had to work in to jam the program into the limited RAM. We could do both floating and fixed point arithmetic.
I am sorry to hear that he died. May he rest in peace.
The PDP series — at least the ones I worked with, starting with the PDP8e — were 12-bit designs, and programming machine code was in octal, (base-8) rather than hexadecimal.
(P.S. Wikipedia also says 12-bit architecture...)
In the early days, DEC built machines with word widths that were multiples of 3.
Without looking up the very earliest models, the ones I am familar with had the following widths in bits:
PDP8/LINC-8: 12 bits
PDP-7/9/15: 18 bits
PDP-6/10/DecSystem10/20: 36 bits
Later, they got with the 8-bit byte / addressable unit program (pioneered, IIRC, by Gene Amdahl at IBM) and built the
PDP-11: 16 bits
VAX: 32 bits
Alpha: 32 bits
By the way, the PDP-8S was a cost and size reduced model of the PDP-8, in that its internal organization was bit-serial. This substantially reduced the number boards/gates/transistors required, at the cost of about a 10X speed penalty. It ran all standard PDP-8 software, however; the programmer’s model was the same as other -8s. I think it was still built with discrete transistor modules. Due to the circuitry reduction stemming from its serial organization, it was the first minicomputer whose main unit fit into a single 10.5” high rack unit.
You are correct that this was still in the days of core memory. I seem to recall that our PDP-8S also had a rack-mountable power supply separate from the main unit, however.
You sir, have outlived most rocks. LOL
Excellent insight into DEC.
Thanks.
Just re-read your post and I think I recall, probably in error, they were using GAL’s in their later products?
Thanks.