[sdiy] CMOS chip questions

[David G. Dixon]

> Unless there are specific needs (certain types of gates not available
> in some sort of logic family), i would go for straight CMOS anyways due 
> to their lower power. Not that it would matter on a single board, but in
> a large modular synth, this would make for the odd amp or two in power
> supply...

I only ever built one circuit with TTL chips, a little square-to-saw
converter on a breadboard.  I was shocked at how much juice it took, even
though the only 5V chips on it were a couple of 7493 counters and a DAC0808.
That's one reason why I'll be sticking with CD40XX and (preferably) 74HC
from now on.

Also, to confirm what's already been pointed out, the 74HCT family is
basically 74HC with logic levels designed specifically to interface with
TTL, so that is probably the preferred option if TTL is unavoidable.