13 Jul
2000
13 Jul
'00
12:26 a.m.
On Wed, 12 Jul 2000 CLASSICCMP(a)trailing-edge.com wrote:
I was looking for a source for some Fairchild
uL914's (DTL NOR gate)
and came across this:
First off it's an RTL dual NOR gate.
When it was about 1.95 in 1969. since it's 4 transistors and 6 resistors
fabricating one using common silicon transistors and resistors is not
a problem.
dictated the SAFEST possible Design for such an
Incredible Mission.
Round 8pin EPOXY package.
Worst reliability of any package I've ever seen.
(I can remember when the local Radio Shack had
blister-packs of uL914's
for probably $.79 each. I believe they sold a "stack-it-yourself" binary
counter kit that used two uL914's for each bit. Anyone got a Radio Shack
catalog from 1976 or so to check my memory here?)
Don't remember the counter but one using RTL used 790p (dual JK FF).
Doing it with 914s was the hard way. Part of the 9xx family included a
buffer/driver(900), JK-FF (923), half adder (903), and several otehr
functions all very cheap in 1970. Moto offered mWRTL aka MC7xx in 14 pin
DIL Package and that included hexinverter, dual jk FF (790p), quad NOR and
an assortment of other building blocks.
FYI these RTL were nominally 3.0 or 3.6V and not low power for the amount
of logic offered.
I still have a large assortment of these as they were good as linear up to
about 3-8mhz and cheap.
Allison