[comp.os.minix] Timing problem with at_wini and WD1006V-SR2?

martin@minster.york.ac.uk (10/20/90)

Hello!
   I am having trouble with the minix at_wini driver on
a Viglen Vig III LS clone. Most of the time it is OK,
but if I do something like:

	dd if=/dev/hd3 of=/dev/null bs=30k

then the machine will usually hang quite quickly, with
the hard disk light perminantly *on*, but with no disk
activity at all!

The bigger the block size, the more likely the machine is
to crash! Also turning off turbo mode seems to make the
crash less likely, but does not avoid it altogether.
This makes me wonder if there is a timing incompatibility
between the at_wini driver and the Western Digital
WD1006V-SR2 RLL disk controller.

Has anyone seen this problem before, or have any suggestions?

To give more details, the machine is a 20MHz 386 clone,
and I have duplicated the problem using both Minix 1.5.10,
and with Bruce Evan's 32-bit patchs installed.
Identical boot floppies work without a problem on a 25MHz
386 box with a WD1006V-MM2 (or at least, did until I
installed a SCSI disk last week!)

Many thanks in advance!

Martin

usenet: ...!mcsun!ukc!minster!martin
JANET:  martin@uk.ac.york.minster
INTERNET: martin%minster.york.ac.uk@nsfnet-relay.ac.uk
surface:
	Dr. Martin C. Atkins
	Dept. of Computer Science
	University of York
	Heslington
	York YO1 5DD
	ENGLAND

feustel@netcom.UUCP (David Feustel) (10/23/90)

How Interesting! I just took my 386 out of turbo mode and suddenly the
AT version of Minix 1.5 doesn't hang when I run FDISK /dev/hd0. I
think you've just found my hard disk problem for me. Thanks!
-- 
David Feustel, 1930 Curdes Ave, Fort Wayne, IN 46805, (219) 482-9631