Yes, its only PIO mode and not UDMA. But my humble point was that someone's used the 8255 as more than just a parallel port adapter.
snipped-for-privacy@yahoo.co.uk (Siddhartha Jain) wrote in
> news: snipped-for-privacy@posting.google.com:
>
> >> >> Then why do Stand-alone MP3-CD player projects like the ones I
> >> >> mentioned below use a IDE controller (Intel 8255A)?
> >> >
> >> > IIRC an 8255 is a fairly simple parallel port adapter.
> >>
> >> I was thinking the same thing. I never thought of the venerable 8255
> >> I/O expander as an IDE controller. I mean try an command the 8255 to
> >> READ DMA and see what it does. :-)
>
> > Well, someone seems to have done it. Check this:
> >
formatting link
> >
> >:)
>
> No, they didn't. This example is PIO. UDMA transfers cannot be
> accomplished with an 8255 acting as the "disk controller". The IDE
> interface in PIO mode is quite similar to a plain old chip selected device
> like an SRAM or FLASH chip so, yes, you can do that with an 8255. Of
> course if you just use a chip with more I/Os then you wouldn't even need
> the 8255.