FDCs (was: MITS 2SIO serial chip?

From: Richard Erlacher <edick_at_idcomm.com>
Date: Mon Dec 17 20:41:32 2001

Gee! ... and I let those guys at Western convince me you couldn't do that.

I've never attempted anyting with Int13, BTW, since I don't hack the PC's. I'm
afraid to break something. I've got a '765-based machine I can experiment with,
though.

Dick

----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin_at_xenosoft.com>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, December 17, 2001 7:21 PM
Subject: FDCs (was: MITS 2SIO serial chip?


> Yes, you can. Correction. I, and others, can. I shouldn't claim that
> you can.
>
> But Int13 won't. That is NOT the same as the chip not being able.
>
> You need to assemble an array of the sector headers that you want.
>
> --
> Grumpy Ol' Fred cisin_at_xenosoft.com
>
> On Mon, 17 Dec 2001, Richard Erlacher wrote:
>
> > There's one advantage that you can exploit with the WD parts that the NEC
parts
> > won't support, and that's formatting with interleaving. The NEC parts seem
to
> > be unable to format a diskette with other than strict ordinal sector
numbering,
> > while the WD allows you to number them with any offset you like. The result
is
> > that an interleaved format optimized for one set of system parameters can
still
> > be read by another system without the other system having to be adjusted in
any
> > way. Of course it won't be able to read an entire track in one revolution,
but
> > it will have the ability to read the diskette without introducing a modified
> > lookup table for sector numbers. I know that doesn't make much difference
> > nowadays, but back when folks used floppies as their main/only storage
medium,
> > it impacted performance.
> >
> > Dick
>
>
Received on Mon Dec 17 2001 - 20:41:32 GMT