24 Aug
2005
24 Aug
'05
6:08 a.m.
Subject: Re: Floppy controller questions
From: Dave Dunfield <dave04a at dunfield.com>
Date: Tue, 23 Aug 2005 22:22:53 -0400
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
There is a way to stop the transfer with out TC. When programming the FDC
command bytes for single sector transfer simply put that sector in as N and
also as EOT. Since the FDC stops reading at EOT it will stop after one sector.
Allison
That's what I wanted. I don't have any
8" drives, so adding support for them
is pointless. Ideally, I want a board that has a 6502-type interface on one
side and a 34-pin IDC connector on the other, with support for most common FM
and MFM 3.5" and 5.25" formats.
I managed to get DMA-mode transfers working, but
never managed to get polled-
mode or interrupt-mode transfers working. Guess I'll have to learn fast when
I start writing code to drive the FDC...
I did polled drivers on the 09 and it worked well. One thing I did find was
that I had to connect a select to the TC pin so that I could pulse it to end
a transfer - I did not find a way to cleanly end a transfer in polled mode
without TC. I can give you the 6809 driver code as well if you want it.