[sebhc] H8 hardware request - docs, info

[Dave Dunfield]

>A couple months ago, I stumbled across the original January 1975 Popular
>Electronics article on the MITS Altair 8800. In my humble opinion, this
>was the "hole in the dike" that started the flood of home computers. It
>was a "real" computer; not a trainer or toy. It was cheap; only $350 in
>kit form, under $100 if you bought the parts yourself and made your own
>boards (the article had the schematics, parts lists, and board layouts
>were free!).
>
>Now, in reality, the 8800 was a *terrible* design, loaded with bugs and
>with no software and no hardware available to actually *do* any of the
>things it promised. Nevertheless, THOUSANDS of people bought them and
>built them, and an entire industry grew up making hardware and software
>to actually deliver on the promise of the Altair 8800. Bill Gates got
>his start writing BASIC for this computer, and the Zenith Z-100 came out
>of its design.

I'd have to disagree with you on "terrible", like the first of anything,
there is always room for improvement, however after 29 years, my 8800 is
still ticking. It has always run reliably (lots of hours on it too), the
front panel has always worked correctly, in short it has functioned as
expected.

I think twice over the years I have had to clean a bit of corrosion out of
some of the socketed IC's on various cards, and once I had to resolder some
of the wires to the CPU front panel connector when I flexed them a bit too
much, (Still using original MITS REV .0 8080 CPU card) but other than that
it has been a most reliable machine. I've had plenty of PeeCee's which have
given up the ghost after much less time.

Lack of add-on hardware and software? This does not reflect "terrible" design,
only the fact that it was the first system of it's type and there was no industry
of supporting material - in fact, the Altair essentually started the industry as
it defined the S-100 bus and made the 8080 CPU available at low cost, both of these
factors contributed to the standardization of hardware and software in the "personal
computer" field. How exactly did you expect a support industry to have developed
before the machine (or the defacto standards it represented) became available?

Yes! I am an Altair fan - I've put many many hours on mine, and did a lot of my
early development on it. (Btw, I Will be posting a page within the next few weeks
which will contain a LOT of defailed information on my 8800).

Btw2, you might want to check the 1975 list price on the Intel 8080 CPU before
sending that $100 through the time machine :-)


>Now, looking at that old article, and looking at the prices that an
>Altair 8800 inspires on Ebay, I got to wondering if one could build a
>*new* version of it. I updated the design a bit, to correct the bugs and
>to use modern ICs that we can get today. I added up the price list, and
>amazingly, the total cost for all the parts and PC boards (less cabinet)
>is well under $100. (The cabinet alone is about $150).

Have you seen the Series-2 IMSAI? They've done pretty much exactly this with the
IMSAI machine (Although I shudder at their discussion on putting ATX boards in
the case). 

http://www.imsai.net/products/imsai_series_two.htm


>To me, the Heath H8 was the Altair 8800 done *right*. It really worked.
>It really did have all the hardware and software to make it a *real*
>computer, capable of doing useful work. The manuals were great! Anyone
>who could read could build it. The design "bugs" were relatively few,
>and fixes for them well-known (gold-plated bus connectors, 0-org, Z80
>CPU, etc).

Funny how different people have different perceptions... My Altair has
"worked" from the very beginning, and continues to do so today. I developed
a great deal of software on that machine. Granted that Heathkit had much
more experience in writing manuals for "build it yourselfers", however I
don't think the Altair documents are bad.  Two years later did wonders for
the H8 software base as well...

I've only recently acquired an H8, so I have not yet formed a real opinion on
it. It too looks like a nice machine, and one I would have been equally happy
to have back in the early days. So far I have been unable to find copies of any
of the cassette software that was distributed with it (I have the manuals), so
I haven't really seen it do anything other than poke around with the front
panel. At some point I would like to port some of my 8080 code (written on the
Altair :-) over to it... (It would really help if I could find a disk controller).


I expect that with either machine there are/were good ones and bad ones - given
the home assembly nature, there would be a lot of variability in the quality of
construction...


>So... would it make sense to build a *new* H8 kit? Update the design to
>include all the basic fixes, and use modern parts (74HC instead 74LS,
>Z80 instead of 8080, modern bytewide memories, etc.).
>
>As for the 8800, I suspect that if I added up all the parts, they would
>cost under $100. The cabinet is the only really expensive part. What
>would you do for it? Substitute something cheap and easy to buy and/or
>make, but that doesn't look anything like the original? Or spend the
>extra money to somehow tool up or build something very much like the
>original?

I wouldn't bother with a "cheap and easy" cabinet - if you are going to
make a replica, do a real replica. I also wouldn't "update the design" to
new devices unless you have to for availability reasons. In the face of
low-cost PC's with gigabytes of memory and 1000's of off the shelf programs
on one end, and flash progammable single-chip devices on the other (for the
simple/control stuff), I doubt there will be very many people who would want
such a system to actually USE it - remaining true to the original would be
more important to me.

A good replica can be the "next best thing" to an original, especially if you
can get the original builder on-board to "certify" the design. There's something
about having the physical box that you just can't get from a simulator. I think
there would be some market for them, but it would be fairly small (I wouldn't
expect to make any money on the project). Unfortunately a lot of the original
parts have become unobtainium now, and the further you remove the replica from
the original, the less interesting it becomes.

There's also the issue of software. Unless you can get rights to the original code,
you would have to provide your own software base for a replica. I have a lot of code
from that time period including OS, Basic, Editor, Assembler, Debugger, compilers etc.
that I would be happy to make available. A fair bit of CP/M and related material is
also available now. It would just be a matter of time and effort to make it happen!

Regards,
Dave
-- 
dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Vintage computing equipment collector.

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