28 Apr
1999
28 Apr
'99
4:14 p.m.
The Heathkit H-8 was made from about 1977-78 to about 1981-82. It was an 8080 computer
(Z-80 boards became available later), proprietary bus [there were a very few 3rd party
source cards]. It originally ran HDOS [Heath Disk Operating System], which was not
compatible with anything; Heath went to CP/M around 1980-81, which required changing the
memory map of the machine [it had it's system ROM in low memory]. The front panel was
implemented in firmware and was octal [thank you Gordon Letwin] [who left Heath for
Microsoft in 1978, after designing much of the Heath architecture and software/firmware].
The system was originally cassette based, then the H-17 was introduced [hard sectored
floppies, SSSD, 100k or so], and near the very end the H-37 components [DSDD 5",
based on a Western Digital controller]. It was an "ok" but unexceptional
machine, inferior to the better S-100 stuff available at the time.
The H-89 and its variants incorporated the same basic architecture in a very user-friendly
"All-in-one" package, and with a Z-80 instead of an 8080 [but only 2 MHz]. The
H-89 was among the most solid, reliable and user friendly CP/M systems available at the
time and made a good, if not fast [even by the standards of the day] business system for
the 1979 to 1982 time frame.
Barry Watzman
----------
From: bluoval [SMTP:bluoval@mindspring.com]
Sent: Saturday, April 10, 1999 2:34 AM
To: classiccmp(a)u.washington.edu
Subject: Heathkit H-8 questions
I saw a H-8 on eBay tonight. What year were these made? What could one
do with it? From the photo it has a 16 key keypad, numbers 1-9 and the
math symbols, decimal point, and 2 others i can't make out. What are
those 2 keys? I'm not trying to buy it, I wouldn't know what to do
with it even if i did. just curious. TIA.
28 Apr
28 Apr
5:09 p.m.
"Barry A. Watzman" wrote:
The Heathkit H-8 was made from about 1977-78 to about 1981-82. It was an 8080 computer
(Z-80 boards became available later), proprietary bus [there were a very few 3rd party
source cards]. It originally ran HDOS [Heath Disk Operating System], which was not
compatible with anything; Heath went to CP/M around 1980-81, which required changing the
memory map of the machine [it had it's system ROM in low memory]. The front panel was
implemented in firmware and was octal [thank you Gordon Letwin] [who left Heath for
Microsoft in 1978, after designing much of the Heath architecture and software/firmware].
The system was originally cassette based, then the H-17 was introduced [hard sectored
floppies, SSSD, 100k or so], and near the very end the H-37 components [DSDD 5",
based on a Western Digital controller]. It was an "ok" but unexceptional
machine, inferior to the better S-100 stuff available at the time.
The H-89 and its variants incorporated the same basic architecture in a very
user-friendly "All-in-one" package, and with a Z-80 instead of an 8080 [but only
2 MHz]. The H-89 was among the most solid, reliable and user friendly CP/M systems
available at the time and made a good, if not fast [even by the standards of the day]
business system for the 1979 to 1982 time frame.
Do you have any idea how many of these units were produced by Heath? Or to
put it more broadly, do you know the production numbers for other Heath
computer products? So far, I haven't heard any numbers and it would be MOST
interesting to at least have an idea! Thanks.
29 Apr
29 Apr
8:15 a.m.
Marvin <marvin(a)rain.org> wrote:
Hi
One of the interesting things about the H89 was that it came
with hard sectored drives and later soft sectored. Many that
used both were impressed with the speed increase. What they
didn't know was that the actual potential was about the same
for both. Because of the way the hard sectored worked, it
couldn't read two sectors in a row. This means that it had
to make one extra rev for each sector. I made a number of
disk for a friend that I interleaved the sectors. He was
impressed with the difference. I always thought that Heath
keep quite about the slight change in formating to keep
the large difference between drive setup to make it look
like the soft sectored were much better when they were only
slightly better.
Dwight
The H-89 and
its variants incorporated the same basic architecture in a very
user-friendly
"All-in-one" package, and with a Z-80 instead of an 8080 [but
only 2 MHz]. The H-89 was among the most solid, reliable and user friendly
CP/M systems available at the time and made a good, if not fast [even by the
standards of the day] business system for the 1979 to 1982 time frame. 
28 Apr
28 Apr
6:23 p.m.
I think the sources to HDOS were put in the public domain by Zenith
back before they disappeared. Are they still around somewhere?
Dave
"Barry A. Watzman" wrote:
The Heathkit H-8 was made from about 1977-78 to about 1981-82. It was an 8080 computer
(Z-80 boards became available later), proprietary bus [there were a very few 3rd party
source cards]. It originally ran HDOS [Heath Disk Operating System], which was not
compatible with anything; Heath went to CP/M around 1980-81, which required changing the
memory map of the machine [it had it's system ROM in low memory]. The front panel was
implemented in firmware and was octal [thank you Gordon Letwin] [who left Heath for
Microsoft in 1978, after designing much of the Heath architecture and software/firmware].
The system was originally cassette based, then the H-17 was introduced [hard sectored
floppies, SSSD, 100k or so], and near the very end the H-37 components [DSDD 5",
based on a Western Digital controller]. It was an "ok" but unexceptional
machine, inferior to the better S-100 stuff available at the time.
The H-89 and its variants incorporated the same basic architecture in a very
user-friendly "All-in-one" package, and with a Z-80 instead of an 8080 [but only
2 MHz]. The H-89 was among the most solid, reliable and user friendly CP/M systems
available at the time and made a good, if not fast [even by the standards of the day]
business system for the 1979 to 1982 time frame.
Barry Watzman
----------
From: bluoval [SMTP:bluoval@mindspring.com]
Sent: Saturday, April 10, 1999 2:34 AM
To: classiccmp(a)u.washington.edu
Subject: Heathkit H-8 questions
I saw a H-8 on eBay tonight. What year were these made? What could one
do with it? From the photo it has a 16 key keypad, numbers 1-9 and the
math symbols, decimal point, and 2 others i can't make out. What are
those 2 keys? I'm not trying to buy it, I wouldn't know what to do
with it even if i did. just curious. TIA.
29 Apr
29 Apr
3:08 a.m.
Upon the date 08:23 PM 4/28/99 -0700, David C. Jenner said something like:
I think the sources to HDOS were put in the public
domain by Zenith
back before they disappeared. Are they still around somewhere?
Ah, Barry and Dave, that's what I barely recall may have happened myself. I
knew HDOS 3 was a project undertaken by several of the HDOS gurus back in
the mid-to-late-1980's but I lost track of it. I can't lay my hands on them
for awhile as they're buried in the depths of my library storage section,
but I recall a lot of discussion in either the BUSS newsletter or SEXTANT
magazine regarding this. There was a bunch of very functional enhancements
to the old HDOS and I wanted to get it, but back then I had few re$ource$.
So, I put my toys away and forgot about them :(
Also, wasn't the Watzman ROM an enhanced H89/90 ROM or was it for the H8?
Danged old age causing brain cells to wander off and get lost . . .
Also once again Barry, recall Trionyx (sp?) Electronics? In Tustin, CA,
IIRC. Bill Perry was the character who owned the company which made several
interesting boards and a rather good high speed motherboard. I bought his
m'brd. for my H8 along with the rather complex C-H8 multifunction disk
controller board which I never got running (his last product). Gotta dig
that board out and do some hacking someday.
Although he had seemingly grandiose dreams for the H8 according to his
style of writing in his sales literature, several of Bill's designs did
work. I never bought his Z80 CPU board, I had the Heath-issue unit. There
were two other third-party CPU board suppliers (D-G Electronics and who
else?) Dang! There goes that brain-rot again . . .
Nevertheless, thanks for reviving a few of my fond old memories of the good
ol' days of Heath Computer Hacking! One could really hotrod his/her H8 or
especially the H89/90. :-) :-)
Dave
"Barry A. Watzman" wrote:
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA cfandt(a)netsync.net
Member of Antique Wireless Association
URL: http://www.ggw.org/awa
The Heathkit H-8 was made from about 1977-78 to about 1981-82. It was an
8080
computer (Z-80 boards became available later), proprietary bus [there
were a very few 3rd party source cards]. It originally ran HDOS [Heath Disk
Operating System], which was not compatible with anything; Heath went to
CP/M around 1980-81, which required changing the memory map of the machine
[it had it's system ROM in low memory]. The front panel was implemented in
firmware and was octal [thank you Gordon Letwin] [who left Heath for
Microsoft in 1978, after designing much of the Heath architecture and
software/firmware]. The system was originally cassette based, then the H-17
was introduced [hard sectored floppies, SSSD, 100k or so], and near the very
end the H-37 components [DSDD 5", based on a Western Digital controller].
It was an "ok" but unexceptional machine, inferior to the better S-100 stuff
available at the time.
The H-89 and its variants incorporated the same basic architecture in a
very
user-friendly "All-in-one" package, and with a Z-80 instead of an 8080
[but only 2 MHz]. The H-89 was among the most solid, reliable and user
friendly CP/M systems available at the time and made a good, if not fast
[even by the standards of the day] business system for the 1979 to 1982 time
frame.
>
> Barry Watzman
>
> ----------
> From: bluoval [SMTP:bluoval@mindspring.com]
> Sent: Saturday, April 10, 1999 2:34 AM
> To: classiccmp(a)u.washington.edu
> Subject: Heathkit H-8 questions
>
> I saw a H-8 on eBay tonight. What year were these made? What could one
> do with it? From the photo it has a 16 key keypad, numbers 1-9 and the
> math symbols, decimal point, and 2 others i can't make out. What are
> those 2 keys? I'm not trying to buy it, I wouldn't know what to do
> with it even if i did. just curious. TIA.
9197
days inactive
9198
days old
4 comments
5 participants
participants (5)
-
cfandt＠netsync.net -
djenner＠halcyon.com -
elvey＠hal.com -
marvin＠rain.org -
Watzman＠ibm.net