22 Oct
1999
22 Oct
'99
7:07 a.m.
Philip.Belben(a)pgen.com wrote:
I was assuming ECL for two reasons - if you use early
transistors
(Ge), ECL would probably be the only way to go at all fast; and ECL
gives the advantage of easy differential line drivers and receivers
for long interconnects.
You're absolutely right. These are the exact reasons that IBM's early
transistor computers (7090, Stretch/7030) used non-saturating logic.
But they did you PCBs with wire-wrapped backplanes.
Their tube computers did not use PCBs, but instead eight-tube pluggable
units that were hand-wired.
And someone will no doubt feel obliged to correct me if I fail to
mention that the earlier IBM machines such as the 603 multiplier and 604
calculator didn't use the eight-tube pluggable units. That was a later
innovation. I'm not sure whether the 650 used them.