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Questions tagged [pdp-7]

For questions about the DEC PDP-7 minicomputer.

This tag should be used for questions about the DEC PDP-7 minicomputer. It should not be used for questions about other computers in the PDP series; separate tags should be used for those.

The DEC PDP-7 was an 18-bit minicomputer, first manufactured in 1965. It had a memory cycle time of 1.75 µs and add time of 4 µs. In total, 120 machines were manufactured and sold.

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Why do the later 18 bit PDPs include both ones' and two's complement?

The PDP-1 is a ones' complement machine, and does some checks to make sure you (almost) never get negative zero. I'm struggling to think why anyone would want ones' complement arithmetic, but it was more popular in the past. Then the PDP-4 came…
Omar and Lorraine
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Is it possible to get a pdp7

Is it possible to get an original DEC pdp-7, if so how much would it be? I've looked around the internet, but I'm not finding anything.
user11220