Just to make sure everything is clear, the Alto has 256K words of 16-bit main memory. It also has 1K or 3K words of specialized 32-bit microcode memory, which i

Just to make sure everything is clear, the Alto has 256K words of 16-bit main memory. It also has 1K or 3K words of specialized 32-bit microcode memory, which is what I'm discussing above. Since you don't do much in microcode, 3K is a fair bit. (Also note that the microcode memory needs to be much faster (i.e. expensive) than main memory.) So the Alto and Acorn are in totally different worlds as far as memory. (Not to put down the Acorn.)