From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca> Right on very few if any! Most went to byte wide or multiples of byte wide... give a guess why? I've always felt that 24bvits was a good starting point for a clean slate machine or a stretched PDP-8. By Stretched 8 I mean just add 12 bits to the right and extend everything else the same amount, gives you a 500k page address and a 16mb machine address. So what if the instruction set is thin if done with modern FPGAs an easy 100ns (12x faster) instruction cycle time would be fine. At 48 bits it gets better as then your not horozontal encoding. Also if you use a prom to do the opcode to microaddress translation it looks nicer and cuts a lot out. Also using the 2901 registers for the PC and all saves a bit too. Still, as you noticed a lof of storage bits for managing traffic are incurred. A combinational state machine is simpler in some respects but far less flexible when it comes to fixing a bent opcode. I can't but, some things still taste bad. ;) Allison