The PREP and PART utilities were available on a
special disk entitled ‘Winchester Utilities
Disk’, distributed separately from the earlier
MS-DOS versions. The disk and instructions are
available from the “
Z-100 LifeLine
” Library.
Caution
: Using PREP is the last resort. It will
destroy all the files that may exist on the hard
drive. If the disk is from another Z-100, you
may need to use PREP only if you consistently
encounter an unreasonable number of disk access
errors. Do NOT use PREP until you have backed up
all important files you wish to keep to floppy
disks.
PREP
has been updated by John Beyers in the
Z-100's Z-DOS v4 that allows it to be much more
flexible in its operation - another reason to
upgrade.
All versions of the PREP utility enable you to:
* Initialize the surface of the hard disk.
* Test the data retention capabilities of the
hard disk.
* Isolate questionable disk sectors.
* Divide the surface of the hard disk into 2
partitions (Z-DOS and CP/M).
PREP takes a long time to run. Expect it to take
about 1.5 hours for every 10 megabytes in hard
drive size. It runs seven surface passes to
check the media and locate bad sectors. These
locations are placed in a Bad Sector Table and
can no longer be used.
Note
: With the version 4 PREP, you can set the
number of passes to make.
If the hard disk does not contain initialization
information (from a prior PREP operation), PREP
will prompt you to enter characteristics (in
hex) in order to identify the type of hard drive
that is being installed in the computer.
Please see the file MFMHardDriveSpecs.PDF on the
Website for a list of common drives that were
used in the Z-100. I have updated this infor-
mation for many more manufacturers.
Note
: Several of the drives are too large for
normal use in the Z-100. Early hard drives and
Z-DOS versions in the Z-100 were limited to
32Mb. Later, with the addition of the PREP /k
switch (which uses 1024 byte sectors rather than
512 byte sectors), the limit was extended to
64Mb. As I understand it, Z-DOS version 4 can go
higher, though I do not recall the limit. Just
remember, larger than 64Mb will ONLY work with
Z-DOS v4. To be able to use these larger hard
drives, the fix is easy - just reduce the number
of heads being used by PREP until the number of
megabytes is where you want it.
Once PREP has completed, if you run ASGNPART 0:
you will see the two partitions created: Z-DOS
and CP/M. If you are satisfied with these two
partitions, you will not need to repartition the
disk with PART.
However, if you wish to change this partition
information, you must run the PART utility.
The
PART
utility is self explanatory. Just
follow the procedures as given to change the
partition names and sizes as necessary, then
choose a default boot partition and save the
configuration to the hard drive.
When complete, you may need to reboot the
computer to the floppy drive again.
Next run ASGNPART 0: to confirm the partitions
are as you required.
Before we can use the new partitions, you need
to assign drive letters to them and then run
FORMAT to do a high level format of each new
partition. Run ASGNPART 0:(partition name) E: to
assign the drive letter E: to the first
partition. Likewise, assign succeeding drive
letters (F:, G:, H:) to the remaining new
partitions (up to four at a time). Run FORMAT
X:/s/v to format and load the system files on
each new partition, where X: can be E:, F:, G:,
or H:.
If successful, you are now in business. Email me
if you have any difficulty. I hope this helps
clarify the use of Z-100 MFM hard drives.
Important
: Hard drives, especially these early
MFM hard drives are fragile and can be damaged
easily.
In all hard drives, while the drive's platter is
spinning, the read/write heads float on a very
thin layer of air separating the heads from the
platter's surface. However, when stopped, the
heads come to rest gently on the surface of the
disk platter.
Any bumping, knocking, or dropping causes the
heads to bang against the surface of the plat-
ter. A severe bump, especially while the platter
is spinning, could actually damage or gouge out
a small area in the platter and cause a "crash",
where an important portion of a program is
unreadable and lost because the disk surface was
damaged.
For early hard drives, it is CRITICAL to run a
disk utility that parks the heads in an unused
portion of the disk - a storage or parking area
- before the heads come to rest. Such a utility
is
SHIP
, an external command packaged in CP/M
and early MS-DOS operating systems.
Later disk drives have an autopark feature that
automatically parks the heads upon power loss.
This article concentrates on MFM drives, which
used the standard hard drive boards found in
most Z-100 computers. MFM drives are recognized
by their two ribbon cable card edge connectors,
one with 34 conductors and the other with 20
conductors.
RLL drives also have these but the drive model
includes an R. For example, an ST-138 is an MFM
drive, while an ST-138R is an RLL drive, with
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