Re: Parallel Card

["mdj" <mdj.mdj@gmail.com>]

bieling@terra.es wrote:

> Matt, if you use a '164 the bits at the parallel output will be
> shifting
> at the same time while the shift-register is being loaded... (not very
> useful unless you're Michael Knight :-)

Indeed, but we're talking about driving LED's, not the TTL inputs of
some other logic device! So the Michael Knight effect isn't an issue -
particularly since it will happen so quickly (in assembly) that it'll
be imperceivable to the human eye ;-)

> A '595 latched shift-register will do the trick: first shift in the
> desired value, and then transfer it to the output latch.

Of course, but this unnecessary when all he wants to do is drive LED's,
unless I'm mistaken and a larger project is in mind. Annunciators
should be used sparingly :-) (Yes, yes you could use the strobe to
drive the clock and save another)

Matt