Perform the following:
[ ] Referring to Figure 13, remove the Z-217
Winchester Controller Board from the card cage
far enough to remove the Format Enable Jumper
from its storage position between pins 3-4 at
the lower left corner of the card and install it
just below the power supply connector. You may
have to disconnect some cables to do this.
[ ] Replace the board in the card cage and
reconnect any cables that had to be disconnected
to remove the board. Make sure that all cables
and boards are fully seated in their respective
connectors.
[ ] If the computer is a Low-Profile model, be
sure to connect the monitor to the computer and
turn it on.
[ ] Connect the line cord and apply power to
the Computer.
Caution
: High voltages are present at locations
around the CRT in the All-In-One computer (See
Figure 8). Avoid touching the picture tube at
the large, single cable attached to the top
surface of the tube!
[ ] Insert the Winchester (Hard Drive)
Utilities Disk in floppy drive A and Boot the
computer. Proceed with PREP.
Note
: I have created a paper listing the PREP
specifications for nearly every hard drive that
could be used in the Z-100. Please see the file,
MFMHardDriveSpecs.PDF, that accompanies this
article.
Once PREP has been completed, you must turn off
the computer, disconnect the line cord, and
reposition the Format Enable Jumper back to its
storage position on the Winchester Controller
Board. Proceed with the following:
[ ] Referring to Figure 13, remove the Z-217
Winchester Controller Board from the card cage
far enough to remove the Format Enable Jumper
from its programming position just below the
power supply connector and install it in its
storage location between pins 3-4 at the lower
left corner of the card. Again, you may have to
disconnect some cables to do this.
[ ] Replace the board in the card cage and
reconnect any cables that had to be disconnected
to remove the board. Make sure that all cables
and boards are fully seated in their respective
connectors.
[ ] Install the cover on the computer.
[ ] Connect the line cord and apply power to
the Computer.
[ ] Reboot and proceed with the PART and
FORMAT utilities.
[ ] Copy the desired operating systems onto
the hard drive.
DRIVING US CRAZY, BUT FOR A REASON
by (C) Alan Brenden, 7/09/92
In the early days of the PC, there wasn't much
involved in deciding when a new hard disk was to
be bought or repaired. The first hard disks used
Seagate's ST506 technology and that was your
choice.
Times and technology have changed and today's
high-performance systems make it necessary to
match the needs of the system to the storage
technology. This article will try to explain
what's behind these drives that drive us crazy -
MFM, RLL, ESDI, IDE, and SCSI.
ST506/412 (MFM & RLL) Interface:
Originally, the ST506 drives used an encoding
method know as Modified Frequency Modulation
(MFM).
As the need for bigger drives evolved, a new
encoding method was developed to pack data
tighter together. Known as Run Length Limited
(RLL), this method involved looking at groups of
16 bits rather than each individual bit. This
achieved a kind of compression of the data that
allowed roughly 50% more on a disk than MFM. The
trade off was that you needed a higher grade of
media and timing was more critical.
As prices for media dropped, RLL drives have
just about wiped MFM drives from the market
place. ESDI, SCSI, and IDE also use a type of
RLL encoding.
ST506/412 drives have 2 cables, a 34 pin control
cable and a 20 pin data cable.
ST506 MFM has a data transfer rate of 625K bytes
per second and a storage capacity of 5 - 100 MB.
ST506 RLL has a data transfer rate of 937K bytes
per second and a storage capacity of 30 - 200
MB.
ESDI:
ESDI (Enhanced Small-Device Interface) was
developed to allow faster transfer rates and
high disk capacities. Greater intelligence
reduced the amount of communication between the
drive and the controller. The transfer of data
between the drive and the controller used a
pulse code that wasn't required to return to
zero between pulses, as did ST506. This was
therefore known as Non Return to Zero (NRZ) and
increased data transfer.
ESDI uses the same cables as the ST506 but the
two can not be mixed. ESDI is CPU controlled and
is suitable for single tasking environments.
ESDI has a data transfer rate of 1-3M bytes per
second and a storage capacity of 80 MB - 2 GB.
One controller can handle up to 2 drives with
multiple controllers possible.
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