Reply to post: Re: Beat the clock

This whopping 16-bit computer processor is being built by hand, transistor by transistor

Nigel 11

Re: Beat the clock

Take a look at a photo of an old enough computer that the CPU consisted of a large number of logic modules connected with a wire-wrapped backplane (for example Google "Images PDP-8 Backplane). You'll soon deduce that the interference problem is not insurmountable. It was not negligible, though!

The routing of wires within the backplane was a black art. Some were artificially lengthened so as to introduce deliberate signal delays. Others took non-parallel routes from A to B to reduce crosstalk - interference is by far the greatest between closely parallel wires. The general term was "random-wired". It was most definitely not a good idea for structure in the circuit schematics to be explicit in the physical arrangement of wires in the backplane.

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