Re: x86 Hardware Trivia Question

On Wed, 28 Sep 2005 22:30:59 -0700, "Charles A. Crayne"
<ccrayne@xxxxxxxxxx> wrote:

>On 28 Sep 2005 21:45:09 -0700
>Chewy509@xxxxxxxxxxxxxxxx wrote:
>
>:Physically, or logically?
>
>Physically, not including any techniques, such as bank switching, which
>require action on the part of a program, or the operating system.

Well, lets see:

64k in I/O space (Bus cycles 2 & 3)
1 meg in code space (Bus cycle 4)
1 meg in data space (Bus cycles 5 & 6)

Plus you could use the Segment Register Status Lines to confuse the
issue even more (4 possibilities)

So, something like 8 meg + 64k, theoretically. :-)
Not including bank switching or such like.

Not sure how usable such a configuration would be, but it could be
interesting to try it.

But, how you get the instructions in to the code space gets
interesting - best use a rom.

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Relevant Pages

  • Re: x86 Hardware Trivia Question
    ... Physically, not including any techniques, such as bank switching, which ... require action on the part of a program, or the operating system. ...
    (alt.lang.asm)
  • Re: code banking
    ... switched memory model. ... You needed to supply the bank switching hardware. ... about 3 or 4 instructions for the switch. ...
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