12 Jun 98, David Shoemaker (Comforce/RhoTech) writes to All: P> Basic problem is rerouting a set of TTL signals into a different P> configuration. P> Ideas / comments welcome. In similar task I use Mitel MT093 / Harris CD22M3493 / SGS M3493 parts. It is 12x8 analog crosspoint switch. Short description follows: The Harris CD22M3493 is an array of 96 analog switches capable of handling signals from DC to video. Because of the switch structure, input signals may swing through the total supply voltage range, V DD to V SS . Each of the 96 switches may be addressed via the ADDRESS input to the 7 to 96 line decoder. The state of the addressed switch is established by the signal to the DATA input. A low or logic zero input will open the switch, while a high logic level or a one will result in closure of the addressed switch when the STROBE input goes high from its normally low state. Any number or combination of connections may be active at one time. Each connection, however, must be made or broken individually in the manner previously described. All switches may be reset by taking the RESET input from a zero state to a one state and then returning it to its normal low state. Tou will need 10 lines to control this chip - 7 address, 1 data (on/off), 1 strobe and 1 reset. Small 18-pin PIC, like 16F84 is good candidate for this switch control. If you need more pins to reroute, you can cascade this swithches in both directions. For digital-only signals, you can also found similar parts in Mitel catalog. Alexey --- GoldED/2 2.50+