On the 370165 and the 36085 4012

Depends on what you mean by "high speed". The 158-168 weren't all that high speed. Yes, I used MECL 10K and 100K (both from Motorola and later Fairchild, IIRC) for clocks for the first LEM-TCM test fixtures for the 3081.

Yes, IBM used +1.25 and -3V, which put the signal swing around ground, so ground could be used as a reference. Motorla used a -5.2V supply, so the signal was -.7V to -1.7V (or some such) with a reference of -1.4. The around-ground signaling and ground as the reference meant that they could get away with a lower signal swing too (ground is less noisy than your power supply).

Logic can *always* be built out of NORs. ;-)

Yes, I was referring to TTL, which is impossible to terminate without special drivers. ECL simply uses a different pull down resistor (impedance match rather than high impedance pull-down), thus "free". When I used MECL stuff I generally used a "split" or thevinin terminator because it was easier than a separate -1.7V terminator supply (IIRC IBM's MST-HPCL used a -.7V termination supply).

If it's a long line with only a single receiver (or receivers close enough) at the end, a series resistor at the source works too.

-- Keith