"David Andrews" wrote in message
news:7yc8f.14224$%A1.10257@trndny01...
Dan,

It is a small embedded controller. I have to design an interface board
anyway.
Problem is mainly with the outputs now. I cant figure out how to expand
the
4 into a greater number.
Im am not worried about the software end of it..



"Dan Hollands" wrote in message
.. .
Hard to offer any advice when you give no clue as to the type of system
you
are talking about
Computer
Data Logger
Controller of some type
etc

--
Dan Hollands
1120 S Creek Dr
Webster NY 14580
585-872-2606

www.QuickScoreRace.com
"David Andrews" wrote in message
news:tpS7f.9607$%A1.9383@trndny01...
I have to expand i/o on a system that now has only 4 inputs and 4
outputs.
I need 12 inputs and 13 outputs.

Anybody got any ideas, i thought this would be easier.
Im familiar with the '249 output latches '151 and input multiplexors
but cant seem to get what i need... ?????





Would a binary to decimal decoder work? Program the four outputs to
be 4bit binary numbers and end up with 16 outputs?
Look at truth table for Fairchild's DM74LS154 chip.
Bart