17 Dec
2001
17 Dec
'01
8:41 p.m.
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(a)xenosoft.com>
To: <classiccmp(a)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(a)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