17 Dec
2001
17 Dec
'01
3:59 p.m.
There ARE many things that the WD will do that the NEC won't, including
writing much sooner after the index pulse, IGNORING certain fields in the
sector headers when reading, and a track read and write (the NEC has a
multi-sector read and write instead of a track R/W)
Allison could probably gives us a more comprehensive and authoritative
list.
On Mon, 17 Dec 2001, Richard Erlacher wrote:
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>
> 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.
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