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Serial PDP-8/e like computer?

>>> The PDP-8/S is largely based on transistorised flip-chips as opposed to integrated circuits.

I was thinking of the W706 and W707 teletype interface cards. Are these the ones that were in the base of the teletype?

Dave
 
This is a rack-mounted PT08 with a custom made variable baud rate generator. It should work with any negibus PDP-8.

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@thunter0512,
I hope this was not already posted, sorry if that's the case, did you see this project of Joe Wingbermuehle?
https://hackaday.io/project/178788-q2-computer
"The Q2 is a complete 12-bit bit-serial discrete transistor computer with a front-panel and user interface implemented on a single PCB using surface mount components.
...
The Q2 is my attempt at a single-board transistor computer. It is a 12-bit design with a bit-serial ALU. It is no coincidence that the architecture is similar to the PDP-8."
 
jplr said:
@thunter0512,
I hope this was not already posted, sorry if that's the case, did you see this project of Joe Wingbermuehle?
https://hackaday.io/project/178788-q2-computer
"The Q2 is a complete 12-bit bit-serial discrete transistor computer with a front-panel and user interface implemented on a single PCB using surface mount components.
...
The Q2 is my attempt at a single-board transistor computer. It is a 12-bit design with a bit-serial ALU. It is no coincidence that the architecture is similar to the PDP-8."
Click to expand...
Thanks - I have seen this before.
A individual transistor based version is interesting, but not what I am exploring.

My goal is to build a TTL IC (SSI and MSI) version of the 8/s with support for an 8/e instruction set.

I was inspired by the series of articles in an Electronics Australia article series by Jamieson Rowe in 1974: Build your own digital computer

Here is a Wikipedia article about it: Wikipedia EDUC-8

The EDUC-8 is functionally very close to a PDP-8/s even though it is a 8-bit CPU. It wouldn't take much to extend the design to 12 bit.
 
@thunter0512 ,

I am a bit late to respond to your original post in this forum, but I have done a fair amount of design work on bit serial processors using widely available 74HCxx logic.

As a rough guide an 8-bit serial machine is going to be about 20 ICs, and a 16-bit cpu is around 30 ICs. This includes ROM and RAM(s).

There is a common core of about 10 or 11 ICS that are needed for any bit serial machine - regardless of the ultimate wordsize.

The PDP-8 at 12-bits will not be dissimilar to a 16-bit machine - as the shift registers used come in 8-bit form.

I have a Github repo - where you can follow my work.

github.com

GitHub - monsonite/SPIder-II: An experimental 16-bit, bit serial computer

An experimental 16-bit, bit serial computer. Contribute to monsonite/SPIder-II development by creating an account on GitHub.
github.com github.com

Or you can find me on Facebook in the Minimalist Computing Group.

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The serial implementation of PDP-8/e is estimated to save 1/3 of chips compared to parallel implementation, but the performance may only be 1/12. I feel that directly replicating the original PDP-8/e is simpler, maybe one qual board is enough
 
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