On Mon, 22 Mar 1999, shevek wrote:
> On Fri, 19 Mar 1999, Laurens Holst wrote:
>
> > What if you want to load code (in Dos) from #0000 using the BDos-routines???
> > Yup, right, you load it in #4000 and then switch it to #0000.
>
> I never tried, but as far as I know the DMA can never be in page 1, since
> that is where the disk-rom is switched during the actual reading
> process... You can load it to #8000, of course :-)
For the most part of diskroms, DMA can be in page 1, because they have
access to FDC through addresses 7FF8h-7FFCh and also BFF8h-BFFCh, and they
transfer a small routine to F1BFh (or something like that) that allows a
disk transfer to happen in page 1.
Greetings from Brazil!
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