On Jul 31, 2011, at 08:20, Robin Vowels wrote: > From: "Don Higgins" <[email protected]> > Sent: Sunday, 31 July 2011 8:26 PM > > >> Do we really need any more opcodes? In college I have a faint >> recollection of learning that all you need to emulate any computer is less >> than 10 basic instruction types like L, ST, A, S, C, BC and SIO. > > You'll also need a few logicals like N, O, SLL, SRL. > I'm not so sure about those. I suspect that in a few hundred instructions N could be synthesized using L, ST, A, S, C, and BC; and so on. Performance would be abysmal, and that's what the new instructions are about: performance.
The PDP-8 had no "L" (or equivalent) instruction. It was necessary to synthesize it from other instructions. -- gil
