The Disk Doctor was developed to diagnose possible disk problems. The
majority of all disk errors is due to it's power supply in some way.
I recomend first checking your 5 volts which powers the boards
connected with the drive. Second, check your 12 volts which powers
the mechanical parts of the drive. If your voltages are OK then the
problem could be bad AC. Make sure that your computer and subsystem
devices and any other device which is connected to your computer is
connected to an Uniteruptable power supply (UPS) with isolated ground.
This could limit shock to any device due to bad AC power . Remember,
current flows to the place of least resistance and many times the
place of least resistance is your disk drive in the middle of a read
or write. Another possible culprit is static , which can travel down
your RS232 or RS422 cable and hit the disk. These villians account for
about 80% of all disk errors. Remember your disk drive was made to
last a reasonable amount of time so you never know when your disk just
might not want to work for you. Please remember to do your backups.
The rule of thumb is backup as often as you can afford to lose data.
The DISK DOCTOR SHOULD BE RUN WITHOUT ANYONE ELSE ON THE SYSTEM. If
you run it with someone on the system you risk the possibility of data
loss if you run the WRITE selection only.
Never is the saying "An once of prevention is worth a pound of cure"
more meaningful than with computers.
1. Help
The help command will display this message. This file is
called DSKDOC.TXT . This file should be placed in the same PPN that
DSKDOC.RUN is run from.
2. Select Drive
The select drive command will allow you to change the logical
you wish to test . The default drive is DSK0: . If you wish to change
this press return when the Select Drive is highlighted . You will be
queried with "Input Drive name Ex. DSK0: >" . You can now select any
logical drive defined on your system . The drive you select will now
be displayed in the lower right hand side of your CRT. Make sure you
include the logical drive number and end with a colon ":".
3. Mounted Drive
The mounted drive command will allow you to display the drives
currently mounted on your system . These are the only drives you can
use for the "Select Drive" command.
4. Read
The Read command will read every block on a logical drive .
While the Disk Doctor is reading you will be updated as to the block
number the Disk Doctor is currently reading . This update is displayed
in either hex or octal depending on which you have set . If you also
have DSKERR set you will be able to locate suspect blocks on your
logical drive. The read command will display the total number of
blocks which will be read in Decimal and the block at which it will
start , which is block 0 in all cases.
5. Write
The Write command will read every block then rewrite every
block on the logical you have specified . If the block cannot be
read then the Disk Doctor will either zero out that block or if unable
to locate that block skip it and goto the next sequential block.
While the Disk Doctor is reading you will be updated as to the block
number the Disk Doctor is currently writing . This update is displayed
in either hex or octal depending on which you have set . If you also
have DSKERR set you will be able to locate suspect blocks on your
logical drive. The Write command will display the total number of
blocks which will be read in Decimal and the block at which it will
start , which is block 0 in all cases.
6. Statistics
The Statistics command will display the statistics for your
drive. These statistics are only going to be valid for the MFM
ST-506 "SASI" type drives . What this command performs is FIXGAR on
the disk driver in DVR: . If you do not have your disk driver in DVR:
this command will not find your driver . If you specify your system
Disk make sure the driver specified during mongen is also called
DSK.DVR . The last information Statistics will display is the amount
of total and contiguous free blocks for this logical.
