27 Aug
2011
27 Aug
'11
2:24 p.m.
Speaking generally though, I'm not convinced Ge
transistors are as much of a
problem as they are sometimes made out to be (..kind of like electrolytic
caps), although yes, they are certainly more of a problem than later/Si.
As an example, the three discrete-transistor calculators I have comprise
about 2000 Ge transistors. 6 of those 2000 transistors have needed
replacement (3 out of over 5000 diodes have also been replaced). These are
from 1966-68 so perhaps a few years later than a 7090, with the potential
for some manufacturing improvements,
Those few years made quite a difference. Even though transistors were
being mass produced as far back as 1952 or so (and I am stretching the
definition of "mass"), they still really sort of sucked until the late
1950s. The transistors in the SMS in a 7090 are really only a couple
of years into the "decent stuff". Your devices from the mid/late 60s
are well past that.
As for my 50000 transistor count, pulled from the IBM website - I
think that is for the CPU only. For a whole system I suspect 70000 is
more like it.
--
Will