Trying to revive a Western Digital File Card 20

By Cèbe, . Permalink Retrocomputing

The "hard disk on ISA" card was a trend in the late 80s.

I've got one sitting there for years. The reference on the ISA card is WDC 61-000347. The HDD itself is a WD93028-X manufactured in September 1989.

It does sound like it could work i.e. no weird noises, spinning OK, heads moving OK but the controller decides that the HDD is toast after just a few seconds. The disk is completely invisible in MS-DOS, so no amount of SpeedStor or SpinRite can help, here.

Something that does seem to work is low level formatting. In a DEBUG prompt, run G=C800:5

This will start the controller card ROM low-level formatting tool. Here is a capture of what's going on screen:

IDE Superbios Rev. 1.0 (C) Copyright Western Digital Corp. 1988 

Current Drive is C:, Select new Drive or RETURN for current.

Current Interleave is 5, Select new Interleave or RETURN for current.

Are you dynamically configuring the drive - answer Y/N y 
Key in disk characteristics as follows:ccc h rrr ppp ee o
where 
ccc total number of cylinders (1-4 digits)
h = number of heads (1-2 digits)
rrr = starting reduced write cylinder (1-4 digits) 
ppp = write precomp cylinder (1-4 digits)
ee = max correctable error burst length (1-2 digits)
     range = 5 to 11 bits, default = 11 bits 
 o = CCB option byte, step rate select (1 hex digit)
     range = 0 to 7, default = 5 
     refer to controller and drive specification for step rates 
782 2 784 784 11 7
Are you virtually configuring the drive - answer Y/N n 
Press "y" to begin formatting drive C with interleave 05
y
Formatting . . .

Do you want to format bad tracks-answer W/N y 
Key in bad track list as follows: ccc h ... 
where
ccc = bad track cylinder no (1-4 digits) 
h = bad track head number (1-2 digits) 
706 0 285 1 178 0
More? Y/N n
                                        BAD TRACK MAP
TRACK ADDR       PROBLEM      TRACK ADDR     PROBLEM
178 0   USER-SUPPLIED         285 1  USER-SUPPLIED
706 0   USER-SUPPLIED

Nothing Done

Restarting

Put DOS disk in A: 
Hit a key when ready.

A few explanations:

  • the interleave depends on the PC you will install the disk in. As it is an 8 bits card, chances are the card is used in a XT class machine, and as such 5 is a reasonable number. Tools like SpeedStor and SpinRite could help find the best interleave, on a functional disk that is.
  • ccc and h are obvious physical parameters of the HDD.
  • rrr, ppp, ee, o are less obvious and explaining them here would be tedious, but I found the correct params for this WD drive.
  • "virtually configuring the drive" means partitioning the drive. Something you would rather do with fdisk, so No is the better answer here.
  • finally the sticker on the HDD actually states the known bad tracks, so I just entered them.

Upon reboot, no fixed HDD is detected and a 1701 error code is displayed on screen.

I resorted to removing the cover of the HDD, as it's not working anyway. Those "low density" drives are not highly dust sensitive, one just has to be careful.

I ran the low level format with the cover off. On visual inspection, nothing obvious is happening. There is no trace of head crash or any other damage on the platters. The stepper motor seems OK too (I did put a drop of oil just in case).

One hypothesis is the heads themselves are failing to read anything.

So, another one bites the dust...

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