Rather neat idea! An Altair 8800 using an Arduino

[Bob Groh]

Just ran across this link in the latest IEEE Spectrum - 

https://spectrum.ieee.org/geek-life/hands-on/build-your-own-altair-8800-personal-computer?utm_source=techalert&utm_campaign=techalert-03-01-18&utm_medium=email 

Now that is a fun idea!  Price is not out of sight either.  How about a version which looks like the Heathkit H-8?  

Bob Groh

Blue Springs, MO. 64014

[geneb]

My kit arrived on Monday. :) It's a well laid out little project and I'm
looking forward to getting it finished.

g.

--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
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ScarletDME - The red hot Data Management Environment
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[Gregg Chandler]

I built my Altair in my dorm room in the spring of 1975. Purchased it in
the fall of 1974, but it took a while to arrive. (I also didn't want to
mess up my classes!) I used my summer job money. Proved to be a good
investment. Ultimately, Bill offered me a job, (which I declined).

One of the Altair's IC's was defective, which a friend, (electrical engineer
and programming mentor from Whirlpool,) fixed for me. It took him a few
minutes with the schematic and a logic probe on his dining room table.(grin)

I thought it was pretty cool that the base Altair had no firmware. The
front panel switches were forcing instructions on the bus. How cool was
that?

By the spring of 1978, I had a DEC-writer and h-8 in my dorm room instead.

Those were the days!

[Norberto Collado]

Thanks for sharing!

"How about a version which looks like the Heathkit H-8?"

>>> Do you mean the H8 front panel with the CPU and I/O on same board?  

Norberto

-------- Original Message --------
Subject: [sebhc] Rather neat idea! An Altair 8800 using an Arduino
From: Bob Groh <bob....@gmail.com>
Date: Thu, March 01, 2018 6:46 am
To: se...@googlegroups.com

Just ran across this link in the latest IEEE Spectrum - 

https://spectrum.ieee.org/geek-life/hands-on/build-your-own-altair-8800-personal-computer?utm_source=techalert&utm_campaign=techalert-03-01-18&utm_medium=email 

Now that is a fun idea!  Price is not out of sight either.  How about a version which looks like the Heathkit H-8?  

Bob Groh

Blue Springs, MO. 64014

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[Lee Hart]

Bob Groh wrote:
> Just ran across this link in the latest IEEE Spectrum -
> https://spectrum.ieee.org/geek-life/hands-on/build-your-own-altair-8800-personal-computer?utm_source=techalert&utm_campaign=techalert-03-01-18&utm_medium=email
> <https://spectrum.ieee.org/geek-life/hands-on/build-your-own-altair-8800-personal-computer?utm_source=techalert&utm_campaign=techalert-03-01-18&utm_medium=email>
>
> Now that is a fun idea! Price is not out of sight either.

It does look nice. :-) It looks like a take-off on Oskar Vermuellen's PiDP-8 (a
PDP-8 front panel clone, connected to a Raspberry Pi running a PDP-8 emulator).
This seems to be a popular notion. There are quite a few of them for various
vintage computers.

> How about a version which looks like the Heathkit H-8?

Indeed, I have been wandering in that direction myself. I was aiming for
something small, with a *real* 8080 (not an emulator). The goal was a pocket H8,
complete with the LED and hex keypad front panel, and able to run HDOS and CP/M
just like an H8. Here is where I'm at so far:

<http://www.sunrise-ev.com/8080.htm>
<http://www.sunrise-ev.com/Z80.htm>

Initially, I couldn't figure out how to make it all fit with an 8080. So I made
a version using the Z80 instead. It's been working for a couple years. Josh
Bensadon wrote the monitor, which is similar to PAM8 but uses hex, which is more
suitable for the Z80 instruction set. It has 64K of memory, a serial port, and
the monitor supports a serial terminal (or PC pretending to be one) for
uploading/downloading hex files or XMODEM transfers.

We then built an Org-0 memory board that includes an SD-card to act as its "disk
drives". It's a work in progress, but is currently running CP/M.

I got enough experience from the Z80 version to go back and take another shot at
the 8080. What I have so far is sort of a cross between a pocket Altair 8800 and
an H8. The software still needs to be written. If anyone is interested in such a
project, we could sure use the help! :-)

--
You never change things by fighting the existing reality. To change
something, build a new model that makes the existing model obsolete.
-- R. Buckminster Fuller
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

[Lee Hart]

Gregg Chandler wrote:
> I built my Altair in my dorm room in the spring of 1975. Purchased it in
> the fall of 1974, but it took a while to arrive. (I also didn't want to
> mess up my classes!) I used my summer job money. Proved to be a good
> investment. Ultimately, Bill offered me a job, (which I declined).
>
> One of the Altair's IC's was defective, which a friend, (electrical engineer
> and programming mentor from Whirlpool,) fixed for me. It took him a few
> minutes with the schematic and a logic probe on his dining room table.(grin)
>
> I thought it was pretty cool that the base Altair had no firmware. The
> front panel switches were forcing instructions on the bus. How cool was
> that?
>
> By the spring of 1978, I had a DEC-writer and h-8 in my dorm room instead.
>
> Those were the days!

That they were! It is truly amazing that we lived through (and indeed, were in
part *responsible* for) a revolutionary change in the lives of mankind. The
microcomputer is as big a step as the invention of the printing press, steam
engines, and electricity.

The computer bug bit me right out of college. I bought the boards for the
"Mark-8" from Radio Electronics magazine. It came out shortly before the Altair,
and used the 8008 microprocessor. But I could not get it working. My knowledge
and skill level just weren't up to the job at the time.

The Altair came out later, by which time I was already committed to the Mark-8.
I eventually gave up on the Mark-8, and built the "COSMAC Elf", which was based
on the RCA 1802 micro (also from a Popular Electronics article). It worked! :-)
I still play with the 1802 to this day.

Later, I bought an IMSAI, and ran CP/M on it. I bought an H19 terminal for it,
which I later upgraded into an H89. The H8 (and a whole succession of other
micros) came later.

I want to find a way to give modern "kids" that same thrill of discovery that I
had. That's why I develop these "old fashioned" microcomputer kits. I want to
get them to *build* things again! And program things themselves!

[Lee Hart]

Lee Hart wrote:
Oops; I mistyped the Z80 link. It should have been
<http://www.sunrise-ev.com/z80.htm>

[Bob Groh]

So now we are on to 'old time' stories.  I started work at Heathkit in the fall of 1977 as a Principal Engineer in the amateur radio department). Almost my first purchase at the company store (which was attached to the main plant - how convenient!) was one the new H-89s.  Delivery was delayed because they were having problems with the disk drive's (interference problems which were quickly solved with a mu-metal shield around the drive which was, of course, mounted in the H-89).  So I got one without the drive and for an agonizing couple of weeks, ran my 'H-88' with a cassette drive.  Finally got the disk drive, ran across a problem with the main board (which I solved and then fed the fix back to the Production people) and finally had my wicked fast disk drive H-89.  And so my adventure began. Got in the 'proof building' cycle at Heathkit for computers - added H-47drives, CPM conversion, virtually every piece of new software went through my hands.  A couple of more H-89s followed, then a couple of Z-100s but now nothing Heathkit around.  Yep, I'm lonely.

Bob Groh

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[Lee Hart]

Bob Groh wrote:
> So now we are on to 'old time' stories.

Sorry! I had just read a story by Terry Perdue on an EDN magazine web
page, which put me in a nostalgic mood. I never worked for Heath; but
built lots of kits and worked for a company making add-on products for
Heath computers.

I keep hoping that the "new Heathkit" will actually do something
impressive; that I'd actually want to buy. So far, I've been disappointed.

Daydreaming... there is so much talent on this list. Members have come
up with all sorts of new boards and devices to repair and expand our
Heath computers. Would it be out of line if *we* made up a "new
Heathkit"? Perhaps an H8, or something similar?

Obviously, we couldn't call them "Heathkits" (unless one of us happens
to be named Ed Heath :-) but maybe something that reminds folks of the name?

Get people to actually *build* thing again!

[dwight]

At least from the doing things, Arduinos and such, are about were things are happening. People are creating a lot of innovative stuff.

It would be hard for any company not in China to compete in that market.

I'm not much of a fan of C or C++ but one can get things done.

My only problem is that too much is hidden in poorly written libraries. For many of us is like a step backwards. Still for someone starting out, I'd highly recommend it.

Dwight

---

From: se...@googlegroups.com <se...@googlegroups.com> on behalf of Lee Hart <leea...@earthlink.net>
Sent: Friday, March 2, 2018 1:59:58 PM
To: se...@googlegroups.com
Subject: Re: [sebhc] Old times...

 

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[Alan Hampson]

I thought it looked pretty nice, too. Unfortunately, by the time I saw the link, they were creating a wait list.

alan

[Lee Hart]

Bob Groh wrote:
> How about a version which looks like the Heathkit H-8?

The Altair 8800 front panel is a *big* PC board, and all those toggle switches
are expensive. An H8 clone would be quite a bit easier.

The H8 front panel PCB is actually big enough to put the entire computer on one
PCB -- keypad, LEDs, CPU, RAM, ROM, serial port, and something like an SD-card
for its disk drive. You could even do it with vintage components (a real 8080 or
Z80). Or an Arduino or Raspberry Pi running emulation software, if that's what
you wanted.

[geneb]

On Fri, 2 Mar 2018, Alan Hampson wrote:

> I thought it looked pretty nice, too. Unfortunately, by the time I saw the
> link, they were creating a wait list.
>

They should have more in soon. The only huge disappointment I have with
it is the lack of a real serial port. All the "serial" ports it has are
tx/rx only, which is effectively useless if you need DTR control or DCD
detect. :(

[geneb]

On Fri, 2 Mar 2018, Lee Hart wrote:

> Bob Groh wrote:
>> How about a version which looks like the Heathkit H-8?
>
> The Altair 8800 front panel is a *big* PC board, and all those toggle
> switches are expensive. An H8 clone would be quite a bit easier.
>

I wouldn't class a switch that can be sourced in lots of 10 for $7
"expensive". ;)

[Lee Hart]

geneb wrote:
> On Fri, 2 Mar 2018, Lee Hart wrote:
>
>> Bob Groh wrote:
>>> How about a version which looks like the Heathkit H-8?
>>
>> The Altair 8800 front panel is a *big* PC board, and all those toggle
>> switches are expensive. An H8 clone would be quite a bit easier.
>>
> I wouldn't class a switch that can be sourced in lots of 10 for $7
> "expensive". ;)

It will depend on whether you want it to look nice; or to actually work.

There are plenty of cheap China switches at low prices. But their
quality is crap. In an application like this front panel, you need a
switch rated for "dry circuit" switching, i.e. low-voltage low-current.
That means gold plated contacts.

Cheap switches don't have gold contacts. They don't even have silver
contacts. The result is that they become intermittent, and don't work
reliably.

I've been building my little 1802 Membership Card for 7-8 years now. It
has a dozens toggle switches on its front panel. When I first started, I
used premium C&K switches, and never had a failure. Then I tried to
China switches; they failed within a year. Worse, the plastic used for
their bodies was so brittle that frequent use would break the bodies. I
quit using them and went back to premium switches.

So, if you just want it to look nice, use the cheap switches. But if you
expect it to be working in years to come, spring for the good ones.

[Alan Hampson]

I know it's been a while, but I did get one of these ordered and built. So, for those who are interested:

The build is pretty easy. Parts come bagged in sets that correspond (mostly) with build steps. There is some wood measuring, drilling, and cutting involved as the case is a  simulated bamboo storage box that you have to create mounting and access holes in. I did most of that with a Dremel and an Xacto knife for cleanup.

All in all, the kit construction was pretty trouble free. I especially liked that in the middle of construction, he gives you some tests you can run to see if you're on track. Helps you know you're good up to that point and satisfies the impatience for seeing the kit work. Construction is pretty quick, as well. It only took me two evenings to complete. 

I also added the rear panel kit and preloaded SD card. The preloaded card isn't strictly needed, but I felt that for $5 it reduced some potential uncertainties if things didn't work right away. The contents of the SD card are floppy and hard disk images you can run from. Lots of great stuff in there including CP/M 2.2, all three Zork editions, and some original Altair business software images.

The only problems I had were a (cheap) USB cable that died after a single use and a missing part (audio jack). I replaced the USB cable with one from my reserve collection (junk box) and the audio jack he sent out to me immediately, so it was here in a couple of days.

The end result of this is a great flashy-light, clicky-switch computer, suitable for generating ooohs and  ahs from your friends. At least if you friends are as geeky/nerdy as mine. :) I've added a couple of pictures.

To me, it was well worth the price, both for the end result and the return to kit building. Now I need to start tackling my stack of Norberto kits!

alan

On Thursday, March 1, 2018 at 7:47:00 AM UTC-7, Bob Groh wrote:

[Bob Groh]

I've got one also but it is still on the bench - got some ham radio projects in front of it so I deliberately holding back on the build (i.e. the build will be a prize for me to celebrate getting some other projects on the way). What are you using for your terminal?

Bob Groh

Blue Springs, Missouri

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[Norberto Collado]

Very nice and thanks for sharing.

 

Norberto

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[Alan Hampson]

That's a nice prize!

For a terminal right now, I'm using the screen command in a bash shell on my Mac via the USB connector. I have plans to try the H-19 portion of the H-89 I just picked up. I also have a Zaurus (Linux PDA) I'd like to get it connected to for the portability, but mostly just for the cool factor. :)

alan