Testing Power Supplies! Re: Norsk Data Nord-10/S restoration effort on the way!

From: Paul Koning <pkoning_at_equallogic.com>
Date: Tue Nov 16 09:23:27 2004

>>>>> "William" == William Maddox <wmaddox_at_pacbell.net> writes:

 William> Paul Koning wrote:
 Tore> But access to a complete array of spares if nessecary. Oh, and
 Tore> the CPU is built in TTL logic, so no hard-to-get spares.
>> TTL is getting hard to find, especially the more obscure types
>> such as 74S series. (And if the book says they want 74S, it's
>> quite possible no other variant will work...)
>>
>> paul

 William> I thought that 74F series parts were generally replacements
 William> for 74S parts. Is this incorrect?

It depends.

Some designs depend on parts being "fast enough". Others are more
finicky. If they need "fast enough" then F or LS or ACT series logic
may well work. If they need "just right" then you have a potential
problem.

For example, some people have used 74S00 devices as crystal
oscillators. Those circuits are less likely to appreciate
substitution.

        paul
Received on Tue Nov 16 2004 - 09:23:27 GMT