Whilst at the Retrocomputer Festival in Cambridge last weekend, I shared a corner of the room with Richard J. Grafton of Arith-Matic.

Richard had spent 30 days in August building a 4-bit breadboarded TTL computer he calls the Cambridge-1.

It's a neat design, which currently uses an Arduino for program loading - but this is to be replaced later with some more TTL logic.

There's some detais on Github here https://arith-matic.com/notebook/4bit-7 ... mputer-cpu

and an introductory video here: https://t.co/Y3vSw8jCUs?amp=1

Richard has posted his progress to Twitter under the @arith_matic handle

https://twitter.com/arith_matic/status/ ... 7821462530

Nice one! I trust you had a good weekend at the event. I was only recently checking out Arith-Matic's work and there was no CPU at that time, only an ALU. I'd like to post this over on the Retrocomputing Forum - unless you'd like to!

Hi Ed,

Richard has been burning the midnight oil for about a month to get the Cambridge-1 together in time for last weekend's RC Festival.

Using an Arduino to help with the Bring-Up is a neat idea ( and also covered well in Ben Eater's latest video on the 6502 https://www.youtube.com/watch?v=LnzuMJLZRdU )

Richard also told me that the Cambridge-1 is a Bitslice architecture and so it should not be too difficult to extend to 8,12,16 bits.

Please share with our friends at Retrocomputing Forum.


Cheers,


Ken

Thanks, shared. This certainly is an interesting machine, and the mission of teaching the lowest levels of computing is a very worthy one.