Re: CBM900 hard disk timeout

From: Clockmeister <>
Date: Sat, 23 Aug 2014 00:30:42 +0800
Message-ID: <>
On 22/08/2014 11:45 PM, Michał Pleban wrote:
> Hello!
> Martin Hoffmann-Vetter wrote:
>> Then this means "controller initialization failed". ;-)
> That is very much possible ;-)
>> I would say, the drive initialize to track 0. The first sectors are on track 0. This must be the partition table at sector 1. So the real partition starts at sector 2.
> That makes perfect sense.
> The computer apparently never tries to read sector 1, or at least it is
> not saying anything about that. It start with sector 2. But let's worry
> about it later.
>> So it's possible, the drive can't step to a specified track. This is the difference between ST412 and ST506. ST412 drives used buffered seek. All step pulses are counted and the drive will moved in one pass to the specified track. ST506 drives seek with every step pulse. Is it possible to switch the WD1003 or the hard drive between buffered and unbuffered seek? In buffered seek you need a SEEK_COMPLETE signal on the control port. If the drive don't send it, it's possible the controller detect a timeout!
> Good point. I noticed that some WD1003 PC cards have jumpers to choose
> one of these stepping mechanism, but the problem is the WD1003-CMD has
> no jumpers whatsoever.
>> Can you step the drive with pulses on the control port manually? You
> need a direction signal (low = inward, high = outward - toward track 0),
> too. After the drive is powered on the READY and SEEK_COMPLETE signals
> must be active.
> Great idea. I will build some circuitry to do that when I get back home.
>> Did you have ask WD?
> I have searched their website and found only documentation for WD1003 PC
> cards. I will send them an email.

What you need is a dump of the controller ROM and check with a hex 
editor to see if  formatting software is present on the ROM.

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Received on 2014-08-22 17:00:02

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