Re: CBM900 hard disk timeout

From: Michał Pleban <>
Date: Fri, 22 Aug 2014 15:07:35 +0200
Message-ID: <>

Martin Hoffmann-Vetter wrote:

> So you mean the message above is a "drive initialization failed" and not a "controller initialization failed". This is a good idea!

The message actually says verbatim: "Controller/drive initialization
failed", whatever that means. I get this message in the above cases.
When I remove the controller, I also get it as the first error message.

What is interesting here is that the first message with the hard drive
jumpered as #0 is actually "Read error" and not "Timeout" as with #1.

> If i remember correctly the data lines from controller and drives are differential lines with a terminiator. Did you checked this termininator on both sides?

The drive does have a terminator. I will check the controller at home
but I a pretty sure the controller should be OK.

> If the data lines are broken or the disk isn't formated, no marker can read. This can issue a timeout.

That makes sense.

A possible hole in my theory is that I see no head movement in the hard
drive after it initializes. So it would either mean that the controller
is unable to step the head, or that after initialization the head is on
the first cylinder so it does not need to move when the computer tries
to read sector 0x00000002 - could that be the case?

For what it's worth, I also get lots of timeouts when I select the "Park
drive heads" in BIOS. It's both the same when the drive is jumpered as
#0 and as #1. I cannot explain that.

> All hard disk controllers have tolerance, so they are not 100% interchangeable. In the 80, when a ship data with hard disks, i put the passed controller with the hard disk.

That's what I'm worried about. Unfortunately the documentation od
WD1003-CMD is nonexistant. In fact, there is only one mention of this
controller in Google, besides my posts...


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Received on 2014-08-22 14:00:02

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