On Thu, 18 Aug 2016 11:04:16 -0500 David Wright <deb...@lionunicorn.co.uk> wrote:
> > In days of yore, there was a minimum distance on coax because > every transmission was effectively a broadcast, and had to pass a > certain distance (≡time) before any reply would be recognised *as a > reply* rather than the transmitter hearing itself transmitting. I doubt that was it. A metre of coax will have a delay of 10-20ns, which was the blink of an eye to hardware of that era. Collisions would have been detected by abnormal levels, which is why termination of the cable was such a big deal. Coax-based Ethernet was basically analogue video technology. Except for, as you say, the damn' stupid 50 Ohms... -- Joe