RasPi Powered ADM-3A Dumb Terminal


[Andrew Curtin] tipped us off to another excellent resurrected vintage one piece ADM-3A dumb terminal. [Andrew] not only resurrected this sexy machine by breathing life into her once more after 37 years but he also got it connected online to retro.hackaday.com for those coveted retro Super Nerd bonus points.

As with other ADM-3A terminals we have seen on Hackaday, the terminal screen can be interfaced over an RS-232 serial connector to a laptop, however, [Andrew] didn’t have a laptop to sacrifice so he utilized the now popular laptop stand-in RasPi. It’s a clever form factor solution which makes it appear more like a standalone computer for the first time in its life.

To make the hack work he needed a serial adapter to link the ADM-3A terminal to the Ras-PI so he constructed one for himself. It’s another clever solution but he didn’t share much information on this build. Maybe he’ll comment below or elaborate on his site with more details on the construction and utilization of the adapter board from the Ras-PI so others could easily repeat this fun hack.

20 thoughts on “RasPi Powered ADM-3A Dumb Terminal

    1. Really? What part of hooking the serial port of a terminal (ADM) up to the TTL serial port of a computer (RasPi) using the reference circuit of the MAX232 TTL to RS232 chip is a “hack”?

      Note that I am NOT belittling what Andrew did. Looks like he had fun, may have learned something, and is proud of it working. Those are all valid reasons to do something. I just don’t see the “hack” part.

        1. But it’s not really “on the Internet”. The Pi is doing all the actual work; the terminal’s just reading keystrokes and spitting out the letters it’s told to.

          Is a 1950s Philco TV “on the Internet” if you connect the Raspberry Pi’s video output to it through an RF modulator?

          1. the difference between the terminal and a TV is that a terminal is also user input. characters entered on the terminal eventually would make their way to the internet, and data from the internet eventually makes its way to the terminal.

            it’s all semantics.

  1. ADM 3A – Data General Nova 3 – *very* expensive scintilation counter.. the local University, courtesy of my dad, let me loose on them all with a soldering iron… aged about 14 to get them all talking over various bits of heavy, screened cable and over engineered 25 way D-type connectors. We got it working, and I was hooked… blinkey flashey lights, machines going beep… :¬)

    Almost invariably the connectors were the wrong gender, almost invariably described in the documentation as DTE when they were DCE and vice versa…. often claiming to need clocks and handshaking signals, when they weren’t striclty necessary.. pretty much everything required “hacking” in some shape or form… IEEE-488 Bus on one gadget, serial interface with proprietory connectors on another.. salesman’s assurance they would talk to each other.. solution.. call in the 14 year old.. data in to 32K Commodore Pet, data out to Data Ganeral… there is always a way..

    ahhh those were the days… these days you need an app (and an Arduino) for everything… (old f*rt sinks back in his rocking chair and continues to ramble until the nurse comes over with his medication… )

  2. I must admit, in the foolishness of my youth, I took a data terminal that very much looked like this, that I had found on trash day, and dropped it off of a railroad bridge onto the street about 70 feet below.

    1. Well.. that’s the thing about these rare retro items. If everyone saved them they would just be obsolete garbage cluttering up way too much of our homes and offices. It’s because most of them are in the landfil or dropped off of bridges, etc… :-) and we just don’t see them every day that the remaining ones are really cool.

  3. I see the nameplate on the left is missing. That’s very authentic; At my school 30 years ago, we had these and the nameplates over the DIP switches disappeared very quickly as there were settings that had to be tweaked very often. At least this terminal was “clean”–most of ours had ink and graphite all over the switches.

  4. I used to repair these in the eighties,nearly always the 1488 or 1489 rs232 chips that were blown.The outfit i worked for were such cheapskates we would fix keyboards by using a soldering iron to melt the plastic and needle nose pliers to pull out contacts from a donor keyboard and insert them in the one that needed repair.

  5. In then 1980’s I built a business of automating hotels by driving up to 24 ADM 3/A’s on a 286 PC. The system was all ASM language and was faster than any competitor. ADM was for “American Dream Machine”.

  6. I see that the lower case character ROM was installed.

    But this is really no hack, it’s just hooking the ADM3 to a Pi. When I saw the headline I thought he had replaced the huge TTL logic board with a Pi.

    I wonder if he could debounce the awful Lear Siegler keyboard with the Pi.

    At my university we had 300 baud modems bolted on top of the ADM3A terminals.

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