Brent Hilpert wrote: Just rumour to me, but circa 1980 when I was doing some software development with the spanky new 68000, I was told that the 68000 had been prototyped as (literally) a large wall of SSI/MSI logic. Billy responds: That was pretty much the modus operandi on early MSI/LSI chips. All of the early ASIC's I worked with were bread boarded from SSI or even single gate ICs. The vendors would provide design kits with lots of these little chips. Most of them were 4 or 8 pins; a few were 14 or 16 pins. You can still buy them today to patch bugs on LSI until you can roll the metal. First ones were TTL, then they moved to CMOS. I even remember one ASIC that we used ECL gates on. This was in the early 80's. Gradually, the design software caught up and you could simulate your design on a computer. It's hard to remember that in the days before PCs, many of tools we take for granted, didn't exist. For example, when CDC was designing the Star series and the ETA machines, the early design automation consisted of huge programs to lay out the logic. The designer input the logic equations on decks of cards. I remember seeing some of these early programs taking 20-40 hours to run, with card decks of thousands of cards. I think I have a few of these early proto boards left. They would make a great display on the progress in the industry. We used a 12" by 24" size and interconnected them with ribbon cable. I never saw a wall mounted unit. But we had many that covered a standard workbench top and they later fit into a 24 pin package. Billy