I have used a serial-in parallel-out along with a latched buffer.
This lets you get as many outs as you want (keep cascading them) for only 3
 pins.  (This is assuming
that speed is not that important.)
PIN 1: Serial Data Out
PIN 2: Serial Data Clock
PIN 3: Latch Clock (so that you only have stable outputs.)

You can use the same trick parallel-in serial-out for input!


HTH,

Alan G. Smith


+---------------------------------------------------------
| Alan G. Smith
| ags@poboxes.com
| http://www.innovatus.com/ags

-----Original Message-----
From: James Bowman <james@SOLEX.CO.UK>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: Friday, October 24, 1997 9:19 PM
Subject: 4-to-16 Decoder?



>What do people use with a PIC16C84?  I've run out of pins.
>