MCCLUSKEY@JPL-VLSI.ARPA (John McCluskey) (05/22/85)
With my own two little hands I wirewrapped a Garry ECL wire-wrap board that ran just fine at 45.5 Mhz after a little tweaking. The tweaking consisted of putting in flip flops to catch signals that wouldn't propagate through three chips in less than 22 nanoseconds. In any case, Augat sez that you can hit 100 Mhz with ECL wirewrap, and I think I'll check that out this summer. I was amazed the first time I looked at rise and fall times on ECL with a scope. The edges are NOTICEABLY less sharp after TWO inches of wire. I guess that God just doesn't like higher harmonics in 50 Mhz square waves. John McCluskey @JPL-VLSI.ARPA ------
nessus@nsc.UUCP (Kchula-Rrit) (05/24/85)
> > With my own two little hands I wirewrapped a Garry ECL wire-wrap board that > ran just fine at 45.5 Mhz after a little tweaking. The tweaking consisted of > putting in flip flops to catch signals that wouldn't propagate through three > chips in less than 22 nanoseconds. In any case, Augat sez that you can hit > 100 Mhz with ECL wirewrap, and I think I'll check that out this summer. > I was amazed the first time I looked at rise and fall times on ECL with > a scope. The edges are NOTICEABLY less sharp after TWO inches of wire. > I guess that God just doesn't like higher harmonics in 50 Mhz square waves. > > John McCluskey @JPL-VLSI.ARPA > ------ *** REPLACE THIS LINE WITH YOUR MESSAGE *** Having worked with ECL(wire-wrapped, no less!) in the past, I must agree with John. What's even more interesting is when you leave the terminator resistors out-- your neat pulses turn into swooping curves almost like pieces of sine waves! It was one of the more interesting types of things I have worked on. Ahh, ECL, one of the few arcane arts they haven't (yet) burned people for practicing. I think the other is analog... From the alter ego of-- Kchula-Rrit