WD2010 failures in Unix-PCs

[Oskar von der Luehe]

In article <31882 at cup.portal.com> chad at cup.portal.com (Chad The-Walrus
Netzer) writes:
>In a previous article (Doug McIntyre) writes
>)	Second. I picked up a WD2010A from a mail order place for the 3085
>)so I can use tracks 1025-1170.. The WD2010A doesn't work with my system..
>)Does the B version work better with these systems? Can I pick up a B version
>)from someone? Is there anything that can modified to make this chip work?
>)I thought the 2010 was about 99% compatible with the existing 1010..
>
>	I have this same problem (ie. WD2010 chip doesn't work) and I'm also
>using the Microbotics 3085, but I have a 2010(B) chip (Not A).  I've tried it
>with two different "B" chips, but neither worked correctly.  I thought it may
>be due to a motherboard incompatibility (I have a Rev. B board) but Thad
>Floryan has said that he has a 3085 running perfectly with a Rev. B
>Motherboard using a WD2010B, so I am at a loss.  What motherboard revision do
>you have?  I want to test the chip and drive on my revision C motherboard to
>see if that has any effect, and I'll let you know what happens.

How about collecting the experiences of those folks who have problems
with the WD2010 in their Unix-PCs? WHAT EXACTLY are the symptoms of
failure? Maybe there is a common denominator, and we figure out a few fixes.

Here is my story, for example.

System:		Unix PC 7300 (that is, *not* the 3B1) with 512 kB on
		main board, and a 20MB Miniscribe 3425 harddisk. There
		were no hardware mods at that time, other than replacing
		the original WD1010 HD controller with the 2010.
		The motherboard has a little sticker saying that it's 
		"Rev. G". Date stamps etc. point at an assembly time
		in summer 1985. Running vanilla 3.51 at the time of
		interest (I have 3.51m now).

HD controller:	WDC '84 WD 2010 B - PL, replacing the original WD1010.

Problem:	System boots fine, no problems with the harddisk drive,
		but the *FLOPP* is gone!!! Any attempt to access the
		floppy drive while running Unix results in a kernel
		crash:
		"panic: gfpwrite: Can't verify write to WD2797"
		The diagnostic floppy won't boot. Needless to say, that
		the WD2797 A -PL is the Floppy controller, which is
		located near to the HD controller.

My first reaction was that I might have zapped something during the HD
controller replacement. But the problem went away when replacing the
2010 with the 1010, so I suspect that the 2010 is the culprit
i.e., not as pin-compatible as advertised. I have no Hardware manual
and only little means to sort out a HW problem by myself. Maybe somebody
knows about a fix.

Oskar

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