IBM PC XT/AT and memory holes

Discussion in 'IBM' started by Vimal, Aug 26, 2008.

  1. Vimal

    Vimal Guest

    I tried to find a copy of the original specifications document for the
    IBM PC XT/AT, but I wasn't able to. I wanted to know what was the
    memory map of the original IBM PC XT.

    I remember reading that the regions from 0xA000:0 till 0xFFFF:7FFF
    were reserved for something other than memory mapped IO.

    Did the concept of memory mapped IO exist in the PC XT at all?

    Vimal, Aug 26, 2008
    1. Advertisements

  2. Vimal

    Cheers Guest


    you might want to ask the question in

    the memory hole you're referring too did exist , from memory, it was
    between 640k(base memory) -- (upper memory) 1024k, this address was
    reserved for other I/os such as mono graphic cards, bios, hd bios
    (rll,mfm)and others.....
    Cheers, Aug 28, 2008
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.