In message <199710250157.VAA01634@vulcan.addy.com>, "Alan G. Smith" writes > 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! The 74HC595 has the latch built-in. Leon -- Leon Heller: leon@lfheller.demon.co.uk http://www.lfheller.demon.co.uk Amateur Radio Callsign G1HSM Tel: +44 (0) 118 947 1424 See http://www.lfheller.demon.co.uk/rcm.htm for details of a low-cost reconfigurable computing module using the XC6216 FPGA