XPost: comp.os.ms-windows.misc, alt.windows7.general, microsoft.   
   ublic.windowsxp.general   
   From: daniel47@nomail.afraid.org   
      
   J. P. Gilliver wrote on 31/12/23 11:37 pm:   
   > In message  at Sun, 31 Dec 2023   
   > 23:17:19, Daniel65  writes   
   >> J. P. Gilliver wrote on 31/12/23 7:27 am:   
   >>> In message <3fj0pi1he28cfgbul4lbmu4jua526btugq@4ax.com> at Sat,   
   >>> 30 Dec 2023 12:10:57, Tim Slattery    
   >>> writes   
   >>>> "J. P. Gilliver"  wrote:   
   >>>>   
   >>>>> For 386 and 486, the confusingly changed what "SX" and "DX"   
   >>>>> meant; on one (I forget which), SX meant it _didn't_ have a   
   >>>>> floating-point maths co-processor on board, DX meant it did.   
   >>>>> On the other, SX meant it had a half-width (so 16?) bus   
   >>>>> outside the chip (so requiring two fetches to   
   >>>> The 486 was the first Intel chip to have the numeric   
   >>>> coprocessor onboard. Intel wanted to prese4ve the "SX" price   
   >>>> point, so they produced a 486SX chip which was identical to the   
   >>>> DX except that the numeric coprocessor was disabled! Machines   
   >>>> sold with this chip had an empty socket where you could plug in   
   >>>> a 486DX chip to get a coproc. So once you did that, you could   
   >>>> unplug the SX chip and use it elsewhere, right? WRONG!!! It was   
   >>>> set up so that the DX in those machines wouldn't work unless   
   >>>> the SX was plugged in, doing nothing.   
   >>>>   
   >>> Did anyone ever manage to "crack" the 486SX or the 487 to enable   
   >>> the disabled part, or make it work without the other?   
   >>   
   >> "487"?? All DuckDuckGo shows seems to concern a Californian Penal   
   >> Code clause 487!! ;-P   
   >   
   > Maybe it was 486DX as Tim says. I had _thought_ the '387 was the   
   > co-processor for that series.   
   >   
   > I'm not sure when they started to drop the "80" from (e. g.) 80386. I   
   > know they started using names around the time of the '586, alias   
   > Pentium, because someone in charge of the administration of   
   > trademarks said, basically, no more trademarking just numbers. (It   
   > wasn't just Intel - other manufacturers had to invent names too; I   
   > remember one chip called "roboclock"; I think it was Maxim or IDT.)   
   > Presumably that's why things moved to Pentium II, etc., rather than   
   > 686.   
      
   (Rumour-mung Rumour-mung) The story I was told, way-back-when, was that   
   in an effort to wipe out Apple and Commodore, etc, Intel virtually gave   
   anybody the Rites and the Chip designs to produce the 80186, 80286,   
   80386 and 80486 Chips.   
      
   Then, having effectively achieved their Aim, when Intel produced the   
   80586, a.k.a. the Pentium chip, IBM required Royalties-type stuff (shut   
   the gate), so some manufactures (AMD, etc.) continued development   
   independently, to produce the 586 and 686 chips.   
      
   It may have also been the case that, as seperate companies were doing   
   their own development, some 586/686 chips had different pin-outs and/or   
   Op-Codes to other 586/686 chips!!   
      
   Something like that.   
   --   
   Daniel   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)