On 2/1/25 13:10, Paul Koning via cctalk wrote:
you might also find high end systems with ECL in
them (-3 volts??? I forgot).
If you ran Motorola ECL the Motorola way, with Vcc at gnd
and Vee at -5.2 for MECL 10K and -4.5 for 100K) logic levels
were -0.8 V for a 1 and -1.6 V for a zero.
If you ran it the IBM MST4 way (Vcc at +1.25 V and Vee at
-3V) then logic levels were +400 mV for 1 and -400 mV for zero.
Jon