Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!ucsd!sdcc6!sdcc10!cs163aeo
From: cs163aeo@sdcc10.ucsd.EDU (Professor I.R. Gumby)
Newsgroups: comp.sys.atari.st
Subject: Re: PC Ditto II -- speed?
Summary: Re: PC Ditto II -- speed?
Message-ID: <107@sdcc10.ucsd.EDU>
Date: 8 May 89 10:36:25 GMT
References: <8905021217.AA08520@nh.cs.wm.edu> <98@sdcc10.ucsd.EDU> <537@TSfR.UUCP> <3944@tekcrl.LABS.TEK.COM>
Organization: University of California, San Diego
Lines: 38

In article <3944@tekcrl.LABS.TEK.COM>, danw@tekchips.LABS.TEK.COM (Daniel E. Wilson) writes:
> In article <537@TSfR.UUCP>, usenet@TSfR.UUCP (usenet) writes:
> > In article <103@sdcc10.ucsd.EDU> cs163afu@sdcc10.ucsd.edu.UUCP (Some call me...Tim) writes:
> > >The initial release of the IBM PC AT contained a 6Mhz 8086
> > >processor.  It was only later that they upgraded to 8Mhz and still
> > >later the 286 processor.
> > 
> >  Wrong.  The IBM PC AT started out at a 6mhz 80286 - IBM only upped the
> > clock to 8mhz when everybody else on the planet was running 8mhz/10mhz/12mhz
> > on their '286 boxes.
> 
>    This may be a shock to you but the PC AT was around long before the
> 80286 was created.  The AT started out with the 8086 and then went to
> the 80186 for a greater clock speed.  Only in recent years has the 80286
> been used in the clones.
> 
> Dan Wilson

 Then we're back to the same question...what the heck is an AT?
Alright, what did this 8086 box have in it?  The ONLY difference
between an 8086 and an 8088 is the size of the data bus, the
instruction sets are identical.  Doesn't make one bit of sense that
IBM would all of a sudden switch processors and architectures on a
particular model of machine.  The marketing power of the AT is the
fact that did have the new (at the time) 80286 chip in it.  If the
AT did have the 8086, then would you mind explaining to me why
there's a such a thing as an XT-286 (basically an IBM XT box with an
80286 chip)?  If memory serves me correctly, the reason this box
exists was because the 286 was available BEFORE the AT was
completed by big blue IBM.  And I have yet to see an IBM AT board
(true blue) with anything less than a 6 MHz 80286 in it, and I have
no recollection of anything other than the original PC having an
8086 and I remember the days the original Apple Lisa was released
with a $10,000 price tag.  If it turns out that the original AT did
have an 8086 in it, it was never marketed (which is a possibility,
but highly improbable considering the XT-286 exists).

 JCA