On 1/27/23 22:19, Neil Cherry wrote:
Similar thinking but with the birth of virtual machines I foresee a x86 forever just because we can emulate it in software or hardware (microcode for example). Of course this is what mainframes have done for the longest time.
Mainframes are microcoded processors, yes, but then nearly all processors are microcoded. We've been implementing processors like that for a very long time. In the PDP-11 world, for example, the only PDP-11 model that's direct-decode (i.e. not microcoded) is the very first one, the PDP-11/20. Every VAX model is microcoded.. If I'm not mistaken, the Broca divide in the x86 lineage occurred with the 8086: The 8085 is a direct-decode processor, while the 8086 is microcoded. -Dave -- Dave McGuire, AK4HZ New Kensington, PA