PC Memory maps (was: Re: 486 w/newer IDE drives)

Sean Conner spc at conman.org
Fri Nov 24 13:07:59 CST 2006

It was thus said that the Great Ray Arachelian once stated:
> The 8086/8088's could only address 1MB of memory, so the 640K barrier
> was a reasonable one at the time despite the infamous "640K ought to be
> enough for anyone" quote attributed to Mr. Gates.
> Of course there was nothing to stop you from installing a RAM card in
> the rest of the I/O space and getting a few more KB, but a better way
> was to use a memory expansion card and bank switch through a 64K window
> to access it, which is what the LIM (Lotus, Intel, Microsoft standard
> was about.

  The major problem with that is MS-DOS---it can't handle non-contiguous RAM
and therefore there is no standard way to reserve or use memory in the upper
384K of the address space (well, for those PClones that followed the IBM

  -spc (Fortunately for me, by the time the 640K barrier would have become
	a problem for me, I was using Amigas and Unix work stations ... )

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