On Fri, 30 Aug 2013, Ed Vance wrote to mark lewis:   
      
    EV> I then remarked, does XT stand for eXpired Technology?, he never   
    EV> thought of that before, but he would tell that to all of his   
    EV> friends who were still running XTs.        
      
   hahaha... XT was eXtended Technology IIRC... it was a step up from the plain   
   original PC... the addition of the HD and the necessary BIOS modification to   
   boot from it were one of the main extensions... also there were more slots (8)   
   on the XT but they were spaced closer together than in the PC... the XT also   
   allowed for more memory on the motherboard (256k) than the PC (64k)... the PC   
   was limited to a maximum of 256k memory whereas the XT could handle up to 1M   
   but only 640k of that was usable by the user... the BIOS, adapter ROM/RAM and   
   video RAM filled the inaccessible 384k of that 1M space...   
      
    EV> That AT of his must had been a 286, I guess.   
      
   yes, ATs were introduced with 6mhz 80286 CPUs in them... they also had the   
   16bit ISA bus as compared to the PC and XT 8bit bus... this also worked well   
   with the 286's 16bit design architecture... the AT also came with a 20M HD   
   (compared to the XT's 10M or 20M in later models)... later the brought out the   
   8mhz 80286 with a 30M HD... the AT's 80286 CPU was specifically designed for   
   multitasking but the huge majority of them were sold and used as single user   
   machines... they were "simply" faster DOS boxes to most folks...   
      
    EV> B4 I got a 486 in 1994, I learned from reading messages on BBSes,   
    EV> and later on, on a ITT XT at work by typing in the Example Programs   
    EV> from the Manuals that came with the XT.   
      
   i started off on a TRS-80 and their BASIC... then later i was downloading   
   BASIC programs from a system up in michigan when i was in oklohoma... i   
   already knew some BASIC so i set about modifying those downloaded programs to   
   add color since i was working on a PCjr with color monitor... later a friend   
   turned me onto PASCAL and ASM and i never looked back... BASIC's PEEKs and   
   POKEs never made sense to me but i knew and understood what they were doing...   
   i was just never able to figure out where folks got those lists of codes from   
   and what they actually meant... it wasn't until i got into ASM that it struck   
   me as to the OPs codes they were using...   
      
    EV> That ITT with DOS 2.11 was a real good PC, in fact when it was   
    EV> replaced by a Zenith 286 I thought the XT worked better than the   
    EV> 286 did.  But what do I know???????????   
      
   the 286 was plagued by a few problems but those were HD based... once the HDs   
   were replaced, they didn't have any more problems...   
      
   FWIW: the 32bit 80386 was brought out by COMPAQ in 1986 IIRC... this was the   
   first time that the (de facto) PC Compatible standard was updated by a company   
   other than IBM...   
      
   )\/(ark   
      
    * Origin:  (1:3634/12)