24 Jan
2008
24 Jan
'08
7:21 a.m.
Hi Roy
Roy J. Tellason wrote:
[ connecting an RLL encoded drive to an MFM controller ]
Yup. Back in those days there were always folks that
tried that, and some
got lucky, while others lost everything on the drive. It's my understanding
that the key point there is the frequency limitation on one of the chips
(read amplifier?) being 5 MHz. vs. 7.5 Mhz, or something like that.
That was an awesome feeling of suddenly being sick that I just had... :)
Here's hoping that since I've not been able to read anything from the disk,
everything's still intact.
Since the card appears to be trying to do *something*
I'm wondering if it's
the BIOS on the card doing it, or that on the MB?
I guess the card BIOS. I've turned off just about everything I can and don't
need on the system BIOS, and the card /is/ doing something - and its behaviour
changes if I plug the drive in the port 1 or port 2. Short of capturing the
output on the control and data cables, I don't think there's any way to prove
this.
One other possibility for getting some meaningful info
that occurs to me is to
get something like TomsRtBt, basically a bootable linux on a single floppy,
and boot that -- then you can poke around and get a pretty good picture of
just what the hardware sees.
Now you're talking. I'm a Linux hacker of eleven years now. The later kernels
(2.6) don't support RLL/MFM controllers, however I'm fairly sure I can compile
a 2.0 kernel and give that a go.
I'll try that at the weekend and report back!
Peter
--
Peter Hicks | e: my.name at poggs.co.uk | g: 0xE7C839F4 | w: www.poggs.com
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