An astonishing old calculator

I've read his book "The Cuckoo's Egg" a few times.

The 'pulse transformer' was actually yhe logic gate itself. There was a three-phase clocking scheme to keep the data flowing to the proper direction. There were few semiconductors, on most panels (huge circuit boards) with only some clock driver power transistors on them.

The basic instruction cycle was 288 us, but only jump instructions used single cycles, so the jump to itself loop sounded at about 4 kHz from the speaker, which was connected to the most significant bit of the instruction register.

Later model 803's used also eight-bit paper tape in the same way as the big brother, Elliott 503.

Awesome!

Tim

It is indeed. It is well worth visiting. It is literally next door to Bletchley Park museum.

There was an acrimonious split a few years ago, I believe due to the Bletchley Park mob wanting to present a "more professional" face, or something. Personally I like the "amateurs" that have detailed knowledge of the exhibits.

Given that the staff are volunteers, I doubt any particular person's attendance is guaranteed. I've only visited twice, on Sunday afternoons, so my experience is limited.

TNMoC also has the world's oldest operating computer, the Harwell Dekatron computer aka WITCH.

Plus the working replica Colossus.

And you can touch the exhibits. The delayed clunk after forcing an ASR33 key down is very evocative.

Yes. Strange and inventive.

I only remember the 576us; I'll check when I dig out my pocket guide to the 803, but you are probably right.

Somewhere I have a cassette tape of the 803 at my local tech college playing tunes. The higher notes were distinctly flat, unsurprisingly. When "fetching Algol" from mag tape it clucked like a broody hen.

He had a good science show on PBS 30 years ago.

I missed it, I saw his TED talk... that gives you a flavor of his 'character'.

George H.

Some juke boxes used cores to store the selected record, one big core per record.

Writing was by X-Y selection, so pushing buttons B-7 queued "Cry me a River". Multiple payments for that song would only play it once. It was nonvolatile, so if some drunk pulled the plug, things would resume after that was dealt with.