Difference between Heath H88 and H89?

From: John Ruschmeyer <jruschme_at_hiway1.exit109.com>
Date: Mon Sep 8 13:00:44 1997

>
> Kai Kaltenbach wrote:
> > Does anyone know what the difference is between
> > an H88 and H89? Externally, they look identical except for the badging.
> > Are they software compatible?
>
> The H88 was a cassette-based Z-80 system. I got one by upgrading an
> H-19 terminal. (I believe you could also buy it as a system.) When you
> upgraded, you replaced the H-19 "badge" with an H-88 "badge".
>
> You could also upgrade the H-88 to an H-89 by adding a hard disk
> controller and floppy disk. When you upgraded, you replaced the H-88
> "badge" with an H-89 "badge".

Actually, a hard disk (H-67) was not standard for an H-89, only floppies
on an H-17 (hard sector) controller.

There are, IIRC, three changes that go into making an H-88 into an H-89:

        1. New BIOS
        2. Replacement of 1 or 2 PALs
        3. H-17 and/or H-67 disk controller.

The cassette is not available in an H-89.

The H-67 Winchester controller was a SASI HD and 8" floppy controller.

There was also an H/Z-90. This was, basically, the same machine with
further revised firmware and an H-37 (soft sector) controller.

If memory serves, you can have any *two* of the disk controllers,
but not all three. My personal machine has an H-17 and an H-37.

One other possibility is that you may have a thied-party disk
controller like the Magnolia. This will require a HW-specific version
of CP/M.

<<<John>>>
Received on Mon Sep 08 1997 - 13:00:44 BST