2022
March 2022
#WEB
Note:
This article was originally published in issue #59, October 1998.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~
Z-100 MFM Hard Drives
PRELIMINARY INFORMATION:
With the proliferation of older computers at
swap meets and electronics surplus houses, now
is a good time to upgrade your Z-100 with a
second hard drive, or if you don't have any yet,
replacing one of the floppy drives in your
machine with a hard drive, though some special
circuit boards are needed.
Since the first 5, 10, or 12 meg hard drives
(called Winchester Drives by Heath/Zenith were
placed in the Z-100 in the mid-80s, there have
been several types developed - MFM, RLL, SCSI,
IDE and others. The drives usually found in the
Z-100 were the first type - MFM - and the sub-
ject of this article. For more information on
the other types of hard drives, I have attached
the article, “
Driving Us Crazy, But For a
Reason
”, by Alan Brenden at the end of this
article.
Another drive type - SCSI - with considerably
larger capacities, became available for the
Z-100 in the late 80s with a SCSI Controller
marketed by CDR. Paul Herman, editor and
publisher of the “Z-100 LifeLine” at the time,
tried to get a special order of boards from CDR
adapted specifically for the Z-100. However, it
soon became evident to Paul, and several
volunteers working as his staff, that they
needed to develop their own controller, and the
new Z-100 LifeLine SCSI/EEPROM board was
created.
As the MFM and newer SCSI systems became more
scarce, attention turned to the newer IDE
technology and another group of volunteers; John
Beyers, Charles Hett, and I. We researched and
developed the new Z-100 LifeLine IDE NvsRAM
board, shipped in late 2008.
You can find additional information on these
newer systems elsewhere on this site. This
article will concentrate on the use of the
initial Winchester hard drive.
The Heathkit/Zenith MFM hard drive installation
was comprised of a Z-217 Winchester Controller
Card in the card cage, a separate, unique Data
Separator Board that was normally mounted near
or over the hard drive and the MFM hard drive
itself. These pictures show the drive tower
configuration possible for the Z-120 All-In-One
Computer ==>
1
