[sebhc] H8 hardware request - docs, info

[Lee Hart]

>> Now, in reality, the 8800 was a *terrible* design...

Dave Dunfield wrote:
> 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'm glad to hear it! It says you are a better technician than I was! For
me, an engineer fresh out of college with little practical experience,
the Altair 8800 was too difficult to get working. It wasn't until
several years later that I was finally able to get my S-100 system
working, mainly by using later S-100 boards from vendors other than MITS
whose boards had better documentation and actually worked as delivered
without a lot of tinkering and troubleshooting.

As in all things, "great" and "terrible" are relative to what you
compare them to. The Ford model T was a "great" car in 1904, and a
"terrible" car in 2004.

However, there is no denying that there is also an absolute sense of
good and bad. Good music, good painting, or good design stands out,
regardless of the years or to what it is compared.

The Altair struck me (and many others, I think) as a diamond in the
rough; a truly great design, but flawed in its implementation. It was
the flaws that got in my way of making it really shine. Others, like
you, managed to work around them.

> 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

I agree. Even I could see that the peripherals didn't exist at first,
but the potential to *add* them was in the original design. There were
lots of computer trainers at the time, but they had very limited
expansion capability. With the Altair 8800, I could imagine adding very
large amounts of memory, or elaborate I/O. In other words, the design
*inspired* me to do more.

> How exactly did you expect a support industry to have developed
> before the machine (or the defacto standards it represented)
> became available?

A truly great design inspires others to copy it, and improve upon it.
The Altair 8800 did this. I *knew* that there would be 64k memory
boards, and floppy disk drives, and CRT terminals.

> Have you seen the Series-2 IMSAI?

Yes. But I think they have taken a wrong turn. It's a lovely, powerful
machine. But it's very expensive and complicated, and still can't
compete with modern PCs.

>> To me, the Heath H8 was the Altair 8800 done *right*.

> Funny how different people have different perceptions... My Altair
> has "worked" from the very beginning, and continues to do so today.

The Altair 8800 was *hard* to assemble. It had *hundreds* of loose wires
connecting the boards. All those toggle switches were hand-wired. There
were one-shots to adjust. The S-100 bus was poorly designed and had
problems like an inadequate number of power and ground traces. The board
layouts were bad, with not enough bypass capacitors, jumper wires and
tacked-on fixes. You had to program it in binary. All of these can be
dealt with by a skilled technician; but they are major roadblocks to a
beginner.

The H8 is basically the same machine, but repackaged to make it far
easier to build and use. As usual, Heath did a great job of writing the
manuals so even a beginner could build it. The design was far cleaner;
it probably took 10% of the time to build. The front panel was octal
instead of binary, which was easier to learn. I think the H8 bus is
better designed, so it is much easier to add memory or I/O boards.

>> So... would it make sense to build a *new* H8 kit?

> I wouldn't bother with a "cheap and easy" cabinet - if you are
> going to make a replica, do a real replica.

The cabinet of the Altair is a generic off-the-shelf Optima enclosure.
It is still available today. But the H8 case used custom molded plastic
and custom sheet metal. It would be very expensive to duplicate it today
unless it was worth paying the thousands of dollars to tool up these
parts. I doubt that there is enough of a market to bother. So, I'm
looking for a work-around.

Also, any cabinet is expensive. When I was a hobbyist, I would buy the
bare boards, and then make/scrounge my own cabinet. This would often
save me considerable money.

> I also wouldn't "update the design" to new devices unless you have
> to for availability reasons.

Heath was great at using generic parts, so virtually all the electronic
components are still available today. However, many of those parts were
used because they HAD to -- better parts weren't available then. But
they are now. Why use eight 4Kx1 RAMs when you can get a single 4Kx8
bytewide RAM? Why use noisy high-power TTL when you can get quiet
low-power HC?

> 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.

Today's PCs are no longer "Personal Computers" -- they are appliances;
inscrutible boxes that no one builds, no one programs, no one
understands.

Everyone has to start at the bottom and work their way up. You learn to
ride a bicycle before a motorcycle. You fly a model airplane before a
real one. And to really learn about electronics and computers, you have
to start with something simple enough so you can truly understand it.

If we expect today's kids to grow up to be tomorrow's computer
designers, they need a way to get started on that long ladder up. The
old Altair 8800, and H8, and other old computers gave us that ladder.
Sure, they were "toys" by modern standards -- but we sure had a lot of
fun (and learned a lot) playing with those toys!

> There's something about having the physical box that you just can't
> get from a simulator.

Exactly! Any teacher can tell you that you learn best when all your
senses get involved; sight, hearing, touch. Just as you can't learn to
play baseball from a GameBoy, you can't learn to design, build, and
program computers from simulations.

> there would be some market for them, but it would be fairly small
> (I wouldn't expect to make any money on the project).

And I don't. My thought is an 'open source' design, that anyone can
download and copy freely. Offer bare boards, or parts kits, or maybe
even a complete kit if the market is there, but keep them reasonably
priced. The whole point is to get people building, and learning, and
having fun with computers again.

> 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.

There is *so* much code out there for the 8080/Z80 that I don't think it
would be any problem. You'd have to avoid Microsoft products, but there
are dozens of alternatives that are public domain. I for one would be
happy to donate any code I wrote to such a project that is to help
people learn and have fun!
-- 
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart  814 8th Ave N  Sartell MN 56377  leeahart_at_earthlink.net

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