My grandpa gave me one of these and also the digital electronics trainer when I was a teenager. He had built them in the 70s. The microprocessor one didn't work but it was probably the first electronics thing that I ever fixed and it was so exciting when I narrowed it down to one of the logic chips using the assembly manual (they were so good!), replaced it, turned it on and the leds said CPU UP. Unfortunately when we moved at some point my mom made me throw out a bunch of stuff and the Heathkits went in the garbage. :(
My father had one when I was a child and my fondest memories are of him building these kits; in my mind, he was a genius. I have all of his kits now and this has just find its way to my to-do list cause I know it's a project that would have been right up his alley. Thank you so much for making it public.
I looked over the Heathkit catalogs as a teenager. We used them in Electronics Eng course in community college, 1987-89. Great throwback and fond memories. Really enjoyed those years.
How cool! I’ve been working my way through “How to Program and Interface the 6800” by Andrew Staugaard, which references experiments with the ET3400 and the Motorola MEK6800D2. Neat to see the Heath model explained!
that ETA-3400 Memory I/O Accessory is very nicely designed and executed. I'm interested in making one now, but with no 3D printer I may have to find someone else to make it.
I always wanted a HEATHKIT E3400 trainer. Funny, i had been working with a dozen different Micros at Boeing back in the late 70's and early 80's, but I still wanted one...
I remember using these at college in the mid 80s and being really pleased because I'd wanted to get my hands on a "hex keypad computer" for ages... I don't know about running BASIC on it is "right". Forth might be OK but BASIC seems somehow "sinful" ;)
Here is IC that came with the Kit from CiE home study course 14-B in 1977. You need to get it and also MC6820P I bought two of these, I got one in 1977 and one just last week, November od 2020
I am building the kit on one of your boards. I am new to the Pi, do I install the basic software (some version of Linux) and then run the Pi scripts on your Github folder? Great project, thanks
The flipchart is part of the Heathkit EE-3401 "Microprocessors" course that is a companion to the Heathkit ET-3400 trainer. The course included two thick binders of printed courseware, two audio cassettes that go with the flipchart, a collection of components that are used in the interfacing experiments (including 2 more 2112 static RAM parts to fill in the second pair of RAM sockets on the ET-3400 and a 6820 or 6821 PIA), and a final exam that you could fill in and send off to Heathkit to be graded and awarded some continuing education credits. There are PDFs of the EE-3401 course, flipchart, and MP3s of the audio cassettes in the files area of the ET-3400 discussion group: groups.io/g/ET-3400
Good day, I have built the Expander. I can't seem to get it to run. I think it is the programming of the f16v8b. What file do I use to in the rom programmer? Thank you
Scott, you did not mention where you obtained the code for the expansion EPROM........? I would offer a correction on your statement about "as high level as BASIC gets".....the original product had only a 'tiny BASIC', so far from full featured. I don't necessarily recall all the differences between the ET-3400 and the ET-3400A, but I have owned both at different times, and I thought the main difference was that the ET-3400 used a 6800 CPU while the ET-3400A used as 6802 or one of the variants that had 256 bytes of RAM built into the CPU....to the ET-3400A PCB had sockets for only two RAM chips because the other 256 Bytes was in the CPU. Seems like they might have used a different keypad as well, although both versions had pretty nice keypads, far better than practically any other single board computer of that era.
The ROMs came from the ET-3400 mailing group (groups.io/g/ET-3400). There's two 2K ROMs, one for the basic and the other for the terminal monitor. It took a little bit of juggling to stick them in a 28C64 in the right places because the addresses are a little odd (0x1400 .. 0x23FF). You're right, it is a pretty basic BASIC, though it does seem to be quite capable for what it is. I think there might be a port of the Star Trek BASIC game that will run on it. Keyboard works amazingly well for something that is 40 years old -- though it does occasionally miss a key and/or register a key twice. I do hope to get my hands on an ET-3400-A one of these days if a nice one comes along at a good price.
@@Brian_Of_Melbourne The one I have now is an ET-3400, the one I wouldn't mind having would be the newer ET-3400-A. There's only small differences between the two.
Nice video. I found an ET-3400 fold-out schematic in my collection. Since I sold my ET-3400, I have no use for it. Let me know if you would like it mailed to you.
Hey Brian, if it's for an ET-3400 (the older model, not the newer ET-3400-A) then I could use one. You might also be able to sell the schematic on eBay.
Good thing you didn't need the serial IO inversion, the Rx inverter is facing the wrong way. Surprised that you didn't also include the likes of an FTDI module to give serial IO on a USB socket as an option rather than the DB25. Something like www.aliexpress.com/item/1005001303615156.html with its right angle connector removed and a straight connector installed from below linking it to your PCB.
Another alternative would have been to use a DB9 -- there are "drop in" FTDI modules that fit the DB9 PCB footprint and would have been a nice form factor for having a USB jack. Ultimately though I decided to stick with the DB25 as that's what the original accessory used, and there's something to be said for the silliness of a 25-pin connector with only a few pins connected. :)
@@rickrickscum2714 Rick, I just realized we never connected. I'm still not sure what address to write you at. If you like, you can email me at smbaker@smbaker.com
@@rickrickscum2714 Thanks. Please don't hesitate to point me toward any Heathkit auctions. Even if it's not something I'm interested in myself, I might always know someone else who is.
I like the "10-key" style layout of the keypad
My grandpa gave me one of these and also the digital electronics trainer when I was a teenager. He had built them in the 70s. The microprocessor one didn't work but it was probably the first electronics thing that I ever fixed and it was so exciting when I narrowed it down to one of the logic chips using the assembly manual (they were so good!), replaced it, turned it on and the leds said CPU UP. Unfortunately when we moved at some point my mom made me throw out a bunch of stuff and the Heathkits went in the garbage. :(
My father had one when I was a child and my fondest memories are of him building these kits; in my mind, he was a genius. I have all of his kits now and this has just find its way to my to-do list cause I know it's a project that would have been right up his alley. Thank you so much for making it public.
I looked over the Heathkit catalogs as a teenager. We used them in Electronics Eng course in community college, 1987-89. Great throwback and fond memories. Really enjoyed those years.
Good trick with the magnets for binding the expansion to the unit.
I learned assembly/machine language using one of these units in college. I periodically look at them on eBay. Good memories.
which college did you goto?
How cool! I’ve been working my way through “How to Program and Interface the 6800” by Andrew Staugaard, which references experiments with the ET3400 and the Motorola MEK6800D2. Neat to see the Heath model explained!
Stauggard wrote the Microprocessor course, easily the best course out of the 20 or so I took to start my 40 year IT career.
I have a heathkit et3400 and this is EXACTLY what I needed
that ETA-3400 Memory I/O Accessory is very nicely designed and executed. I'm interested in making one now, but with no 3D printer I may have to find someone else to make it.
That's too cool, I have one from EBay coming also! The + & - 12V was used for a 741 opamp input for one of the experiments
I always wanted a HEATHKIT E3400 trainer. Funny, i had been working with a dozen different Micros at Boeing back in the late 70's and early 80's, but I still wanted one...
Fantastic Demo... I have one too In my heathkit collection.
If you could write to the eeprom just like ram. You could write the programs to the eeprom and build your own toolbox of routines.
Anyone else notice that the thumbnail says the video is an hour long yet in player says 42 minutes?
I remember using these at college in the mid 80s and being really pleased because I'd wanted to get my hands on a "hex keypad computer" for ages... I don't know about running BASIC on it is "right". Forth might be OK but BASIC seems somehow "sinful" ;)
Here is IC that came with the Kit from CiE home study course 14-B in 1977. You need to get it and also MC6820P
I bought two of these, I got one in 1977 and one just last week, November od 2020
that is pretty cool. I almost bought one last year but the price was too rich.
I am building the kit on one of your boards. I am new to the Pi, do I install the basic software (some version of Linux) and then run the Pi scripts on your Github folder? Great project, thanks
Good show....What 3d printer are you using? I am looking for something with a larger bed than my 6 x 6"
Thanks !
That flipchart is cool. I'm going to have to search for a pdf on the web.
The flipchart is part of the Heathkit EE-3401 "Microprocessors" course that is a companion to the Heathkit ET-3400 trainer. The course included two thick binders of printed courseware, two audio cassettes that go with the flipchart, a collection of components that are used in the interfacing experiments (including 2 more 2112 static RAM parts to fill in the second pair of RAM sockets on the ET-3400 and a 6820 or 6821 PIA), and a final exam that you could fill in and send off to Heathkit to be graded and awarded some continuing education credits. There are PDFs of the EE-3401 course, flipchart, and MP3s of the audio cassettes in the files area of the ET-3400 discussion group: groups.io/g/ET-3400
my house electricity is 240v, and the device is 120v, what to do? help me.
Good day, I have built the Expander. I can't seem to get it to run. I think it is the programming of the f16v8b. What file do I use to in the rom programmer? Thank you
would you consider to sell your version of the ETA-3400 as a kit including the PCB, the 3D parts and the electronic parts?
Scott, you did not mention where you obtained the code for the expansion EPROM........?
I would offer a correction on your statement about "as high level as BASIC gets".....the original product had only a 'tiny BASIC', so far from full featured.
I don't necessarily recall all the differences between the ET-3400 and the ET-3400A, but I have owned both at different times, and I thought the main difference was that the ET-3400 used a 6800 CPU while the ET-3400A used as 6802 or one of the variants that had 256 bytes of RAM built into the CPU....to the ET-3400A PCB had sockets for only two RAM chips because the other 256 Bytes was in the CPU. Seems like they might have used a different keypad as well, although both versions had pretty nice keypads, far better than practically any other single board computer of that era.
The ROMs came from the ET-3400 mailing group (groups.io/g/ET-3400). There's two 2K ROMs, one for the basic and the other for the terminal monitor. It took a little bit of juggling to stick them in a 28C64 in the right places because the addresses are a little odd (0x1400 .. 0x23FF). You're right, it is a pretty basic BASIC, though it does seem to be quite capable for what it is. I think there might be a port of the Star Trek BASIC game that will run on it. Keyboard works amazingly well for something that is 40 years old -- though it does occasionally miss a key and/or register a key twice. I do hope to get my hands on an ET-3400-A one of these days if a nice one comes along at a good price.
@@smbakeryt Did you really mean to say "get my hands on an ET-3400"? Surely that's what you've got already?
@@Brian_Of_Melbourne The one I have now is an ET-3400, the one I wouldn't mind having would be the newer ET-3400-A. There's only small differences between the two.
Nice video. I found an ET-3400 fold-out schematic in my collection. Since I sold my ET-3400, I have no use for it. Let me know if you would like it mailed to you.
Hey Brian, if it's for an ET-3400 (the older model, not the newer ET-3400-A) then I could use one. You might also be able to sell the schematic on eBay.
Good thing you didn't need the serial IO inversion, the Rx inverter is facing the wrong way.
Surprised that you didn't also include the likes of an FTDI module to give serial IO on a USB socket as an option rather than the DB25. Something like www.aliexpress.com/item/1005001303615156.html with its right angle connector removed and a straight connector installed from below linking it to your PCB.
Another alternative would have been to use a DB9 -- there are "drop in" FTDI modules that fit the DB9 PCB footprint and would have been a nice form factor for having a USB jack. Ultimately though I decided to stick with the DB25 as that's what the original accessory used, and there's something to be said for the silliness of a 25-pin connector with only a few pins connected. :)
I have six of these and some others brand new in the box never put together with all the papers. Contact me I seen your ebay listing
Where can I contact you?
Let me know here when you message me so I can open it then send you the pictures
@@rickrickscum2714 Rick, I just realized we never connected. I'm still not sure what address to write you at. If you like, you can email me at smbaker@smbaker.com
I sold them but I'm getting more soon. They sold in ebay listing for 600
@@rickrickscum2714 Thanks. Please don't hesitate to point me toward any Heathkit auctions. Even if it's not something I'm interested in myself, I might always know someone else who is.