Eric Smith wrote:
"Paul R. Santa-Maria" <paulrsm@buckeye-express.com> writes:The IBM PC came out in 1982.August 1981. I don't remember what day, but my then-employer purchased one from a local Computerland store on the day of introduction. That was when I got my first introduction to 8086 architecture (blecch!). Fortunately the 386 introduced a much cleaner 32-bit flat addressing model, and the Athlon 64 and Opteron [*] have done a good job of extending it to a 64-bit model with more general registers. There's still a lot of legacy baggage for 8086 and 80286 in the chips, but if you're writing new code that doesn't have to run on the pre-386 chips, you can mostly ignore it. Eric [*] Oh, and Intel has some parts in which they've cloned the AMD 64-bit instruction set, though they screwed up a few things. Intel calls their version EMT64 or some such thing. Once upon a time, Andy Grove of Intel publicly quipped of AMD that "their last original idea was to copy Intel." The shoe is on the other foot now.
A substantial part of Intel (but certainly not all) intended to leave the IA-32 architecture behind in moving to 64 bits, but a hedging strategy and relatively poor execution on the IA-64 side seem to have doomed them to dragging their albatross forever--much to the joy of the many x86 fans at Intel. By all rights, we should be entering an age of "virtual architectures", where both new and legacy code files are translated for execution on the fly, and dynamically optimized to the host architecture, whatever it is. This would mark the end of architecture dominions, and the true merging of instruction set architecture and microarchitecture. Apparently this future will have to wait for manufacturers, who are greatly aided by the unrelenting inertia of the installed codebase, to lose the battle to newer implementations. (And Transmeta clearly isn't that newer implementation. ;-) -michael Music synthesis for 8-bit Apple II's! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it is seriously underused."