--- Cameron Kaiser <spectre_at_stockholm.ptloma.edu> wrote:
> > P.S. When OS/2 came out, what really impressed me about it was its
> > ability to format a floppy disk and *NOT* slow down every other process
> > running...
>
> I was amazed by the fact that floppy access on an Amiga does *not* slow
> the system either. It was merrily copying files around and everything
> was totally responsive. And this was on a original, ho-hum A500.
Sort-of. If you were at the regular Workbench screen, two bitplanes,
yes. There's ample DMA bandwidth for video and floppy. If you were
trying to do floppy operations from an application that was running a
4-bitplane Hi-res screen, that would give you problems.
I'm pretty sure that Wintel machines have problems with trying to
walk and chew gum at the same time because the low-level routines
suck - they block for I/O, because, why would you *need* to do two
things at once, anyway? PeeCee floppies will do DMA, but I think
the BIOS driver waits for the DMA to complete before twiddling the
control lines. The Amiga, OTOH, was designed to keep things rolling;
its drivers don't lock up the machine waiting for an I/O to complete.
-ethan
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Received on Wed Jan 09 2002 - 14:46:34 GMT