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

[Paul Koning]

>>>>> "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