<PROM, or maybe one of those TI PALs with the 74-series numbers'. I said <'No, I can do it with a normal 16 pin TTL chip that doesn't have to go <in <a programmer first'. So, what was the chip ? < <74LS138, 1 of 8 decoder, the three inputs go to A, B, C, all 8 <possibilities decoded on the outputs. < Jack Peacock How about 74153 or 74155 real handy for creating complex miniterms that a small prom or pal might be used for. Allison