8 Sep
1997
8 Sep
'97
8:03 a.m.
Just when I think you can't find any genuinely old computer stuff in
thrift stores anymore, I come across something that changes my mind.
This weekend it was a beautiful, mint condition Heath H88. Don Maslin,
keeper of the CP/M disk archives, has CP/M for the Heath H89, but
doesn't list the H88. Does anyone know what the difference is between
an H88 and H89? Externally, they look identical except for the badging.
Are they software compatible?
thanks
Kai
8 Sep
8 Sep
8:32 a.m.
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".
So, it's quite possible that not only do they look identical externally,
they look identical internally. If what you saw DOESN'T have a floppy
disk, then maybe it is the cassette-based system. Look inside. I have
the cassette software, if you are masochistic enough to want a copy of
it.
You might be able to find a hard disk controller and make it into an
H-89, if you like. It shouldn't be too hard to find a floppy drive that
works, just plug in a DEC RX50 dual floppy! My H-89 has in fact the
original prototype (DAM Drive) of the dual floppy, made by T and E
Engineering. DEC later bought them out for the Rainbow/uPDP/uVAX, etc.
If you need an RX50 drive, I can get you one.
Dave
8:52 a.m.
Opps! Read "floppy disk controller" for "hard disk controller" in
the
original reply.
David C. Jenner wrote:
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". 
9 a.m.
Kai Kaltenbach wrote:
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>>>
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".
10184
days inactive
10184
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3 comments
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djenner＠halcyon.com -
jruschme＠hiway1.exit109.com -
kaikal＠MICROSOFT.com