[BC] BE FM-35A

[Tom]

And if the supply is other than +5V TTL, you can get the CMOS versions 
of the TTL chips; the 74C series is pin-equivalent to the regular 74-xxx 
series - IIRC, ALL the 74-type logic chips are pin equivalent, 
AAMOF...and will generally work .

OTOH, the reverse isn't always true - if the HC was the original, you're 
pretty much stuck; standard C won't work reliably - or at all, forex.

There's even differences in the TTL stuff... I have two Audioarts A-50 
boards that use 74-series dual flipflops; suffix N - regular dual FFs 
won't work in-circuit, although I suspect if I did some experimenting, I 
could figure out WHY the standard chips don't work...



Glen Kippel wrote:
> I once had to keep up an automation brain that used RTL.  I found that these
> could be replaced with TTL chips with no problem.  It's a handy hint that I
> thought I'd pass along in case anyone else here has to deal with obsolete
> equipment.
-- 
Tom Spencer
PG-18-25453 (nee' P1-18-48841)
http://radioxtz.com/
Part 15 transmitters on AM 640 and FM 100.1