MFM Hard Drive Installation
DISASSEMBLY:
Installation of a hard drive requires partial
disassembly of your computer. As disassembly and
reassembly are beyond the scope of this article,
please refer to your Z-100 Users' Manual or the
‘
About Z-100 Computer
’ on this website for these
procedures.
Caution
: In the All-In-One Computer, high
voltages are present around the large wire
attached to the top of the picture tube.
For the Z-110 Low-Profile Computer, remove the
cover and drive assembly. For the Z-120 All-In-
One Computer, remove the cover and the CRT/drive
assembly. Set these aside.
From here down internally, both models are the
same. The card cage, with its removable vertical
boards, such as the Z-205 RAM Board or Floppy
Controller Board, is to the rear of the compu-
ter. A large motherboard fills nearly 3/4 of the
computer's bottom with a much smaller video
logic board mounted horizontally on 3 standoffs
on the motherboard.
One or two smaller boards, such as a Gemini
PC-Emulator Board or an 8087 co-processor board,
may be sandwiched between the two.
Before attempting to install a hard drive in a
Z-100 computer, ensure that the power supply has
the proper cables for the Data Separator and the
Z-217 Winchester Controller Boards. These may be
folded up and stored to the side.
Figure 1.
Power Supply Connectors
Also ensure the proper PAL and ROM integrated
circuits are installed, using the following
procedures:
Caution
: Refer to the Z-100 Users' Manual for
the proper procedures on handling integrated
circuits (ICs). Many ICs are metal oxide semi-
conductors (MOS) which can be damaged by static
electricity.
[ ] Remove the three small screws attaching
the video logic board horizontally across the
motherboard and swing it upward onto its back
edge (carefully lean it against the card cage).
Note
: Read the following steps carefully. You
may already have the correct ICs installed in
your motherboard.
[ ] Locate the PAL IC (U161) on the mother-
board. If the part number on this IC is lower
than 444-129-1 (such as 444-129), the IC must be
replaced before installing a hard drive.
[ ] Locate the Monitor ROM (MTR-ROM or ZROM)
IC (U190) on the motherboard. If the part number
on this IC is lower than 444-87-5 (such as 444-
87, 444-87-1, -2, -3, or -4), the IC must be
replaced before installing a hard drive.
Note
: Newer power supplies, hard drive boards,
PALs and ROM chips are available from the "
Z-100
LifeLine
".
[ ] If you are installing a ZROM v3.x monitor
ROM (or later) at U190, locate the programming
jumper J102 on the left edge of the motherboard,
about half way from the front to the card cage.
Unplug it from the 0 position and reinstall it
in the 1 position, if this has not already been
done. This jumper recognizes the higher capacity
of the newer ROM chip. Be careful not to disturb
the setting of programming jumper J101.
[ ] Locate switch S101 on the motherboard and
set each switch to the 0 position (toward the
card cage or rear of the computer), if this has
not already been done.
Note
: Section 7 of this switch sets the refresh
rate of the display RAM and is normally set to
the zero position for 60 Hz (in the U.S.). If
you live overseas and your AC line frequency is
50 Hz, you must set this switch section to 1.
[ ] Locate the part number on the motherboard
(near U190). If this part number is 85-2653
(disregard any other number that may follow,
such as 85-2653-1), you have an older mother-
board that will require several modifications.
These modifications are available from the
"
Z-100 LifeLine"
, but involve soldering on the
board.
Note
: The "
Z-100 LifeLine
" has plenty of the
newer motherboards at reasonable prices (See the
pricelist on the “For Sale” page of the Website.
[ ] Reinstall the Video Logic Circuit Board on
its three standoffs and secure it with the three
screws.
PREPARING THE MFM HARD DRIVE:
Note
: While the hard drive may be installed
first, I find it is best to prepare the hard
drive and ensure it is working properly BEFORE
taking the time to install it. Earlier, I showed
two pictures showing how the hard drive may be
placed temporarily on the power supply during
preparation.
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