Where Did Pocket Computing Start?

A smartphone in 2019 is an essential piece of everyday equipment. Many of you are probably reading this page on one, and it will pack a very significant quantity of computing power into your hand. Pocket computing has a long history stretching back decades before the mass adoption of smartphones though, and Paleotronic has an interesting retrospective of that earlier history.

The piece starts with the Radio Shack PC-1, a rebadged Sharp with a calculator-style keyboard and a one-line alphanumeric LCD display, then continues through the legendary TRS-80 Model 100 to the era of the palmtop. It’s a difficult subject to cover in its entirety as there are so many milestones on the pocket computing path, but it’s an interesting read nevertheless as it successfully evokes the era when a 300 Baud connection via an acoustic coupler was a big deal. We might for example have mentioned the Atari Portfolio if only for its use by a young John Connor to scam an ATM in Terminator 2, and as any grizzled old sysadmin will tell you, there was a time when owning a Nokia Communicator might just save your bacon.

Of the classic pocket computing devices mentioned, only one has received significant coverage here. The TRS-80 model 100 still has a huge following, and among quite a few hacks featuring it we’ve seen one brought into the smartphone age by getting the ability to make a cellular connection.

TRS-80 Model 100 image: Jeff Keyzer from Austin, TX, USA [CC BY-SA 2.0]

36 thoughts on “Where Did Pocket Computing Start?

  1. My brother had an Epson HX-20, which was a similar size to the Tandy Model 100, and predated it by a couple of years. He used to write adventure games on it for me to play. He still has it in his ‘retro computing museum’ (closet).

    1. I’ve never seen it as a mechanism before,
      I’d only seen it (and earlier version) as a bunch of “sticks” that could be positioned next to each other.
      Thanks for the link!

      Okay, who has the STLs for this?
      B^)

  2. An Epson HX-20 plus barcode wand, tapes, and full user manuals for sits in the closet. First reasonable portable computer. Appreciate you knocking that memory loose. Was fun days.

  3. If you’re talking full-size keyboard, there were a few portable electronic typewriter derived devices, not necessarily with integral printers, which could be used on the move as a terminal with an acoustic coupler that were available early 80’s. .Definitely a Brother and a Toshiba with bubble memory and large LCD screen. Not really my idea of pocket computing though. The first pocket computer, date-wise, was, I reckon, the Psion series 1.

    1. The Model 100 was crazy good at telecomms. It could do 5, 6, 7, or 8 bit serial out the RS232 port, with 0/1 stop bits, and whatever parity scheme you want. It would also run for hours on four AA batteries, and had ~21KB of nonvolatile (I’m thinking battery-backed-up) memory. I hacked together a BASIC program to log up to eight hours of LORAN data on a road trip. Fun little machine.

    1. This. I still have a PSION Organizer II, fully functional. My father was part of a failed startup in the late 1980s that would have developed and marketed various add-on gadgets for it… you’d be amazed at what that thing can do.

  4. I had an HP-95LX which I replaced with a used HP-200LX many years later. And more recently I got onto an indiegogo for the Gemini PDA which was an Android clamshell computer inspired by the old Psion devices. Sadly I dropped it several times and the spacebar fell off.

    1. Ditto on the 95LX, got mine while working for HP. For hacking, it had a functional serial port of which I used the serial terminal to gather data from a Basic Stamp datalogger project many moons ago. Never had a 200, but definitely wanted one.

    2. Modern phones are comparable in screen size to the old Psion computers. I’d really love to find keyboard cases for them, similar to the keyboard cases made for iPads and Surface tablets.

  5. I bought a Radioshack PC-1 when I was 13 and I had a blast with it and even bought a plotter to play with.
    People always said “Nice device your parents bought you” and I cut them off reminding them some of us kids didn’t get an allowance so had to work paper routes, shovel snow and mow lawns to make our money.

    1. I recall walking into an electronics store and putting $10 lay away on a ZX-81 computer kit. I worked at a gas station cleaning the crapper and sweeping floors and every penny earned went towards the ZX-81.

  6. I have the Model 102. I kept this computer for a future robotic music project. I love that it works on AA batteries for a very long time. BTW i need to see if there is any flash memory hacks for it.

    1. Did you not get NDA update/renewal? Ha. Most of the data logger/field data entry units (bricks) that preceded the publicly available ‘stuff’ will most likely be left in abyss. Many of which made these public offerings anemic, pale, woefully inadequate and outmoded even at that time.

  7. Nice, that TRS-100… Never had one, in fact I always wanted to get the Epson PX-8… That was such a cool machine at a time when “portable PC” meant “sewing machine size/weight”. Unfortunately I never had the money for one back then.

  8. An early history of pocket computing centered on the US market, with rebadged Japanese calculators. Casio had released programmable pocket calculators in the 70’s already, notably the FX-502P in 1978, but it didn’t have a qwerty keyboard. HP did also release several interesting machines before that using RPN (reverse Polish notation) for the most hardcore programmers.

    Like the Sharp models, some Casio models were rebadged under the Tandy brand (PC-4 to PC-8). Some years later Casio released graphic programmable calculators, notably the fx-7500G/fx-8500G which were very popular in my country (France). It was at a time when you could contact big manufacturers like Casio and they would send you datasheets of their calculators for free from overseas without asking any question. Great times, it allowed me to reprogram the character generator to create a 1vs1 chess game and helped gather enthusiasm around an online user group on Minitel in the late 80’s.

    I started with the FX-780P which was a pure joy at the time. I still have it (but it’s becoming capricious) and a FX-795P sitting on my desk that I still occasionally use when Windows calc is too limited.

  9. And I have a TRS-80 Model 102 here that is a rescue. That’s right it was rescued from a computer recycling outfit that had no idea of what it was, or would be able to do. I’ve used it as a serial console for a Raspberry Pi rig, as described in an article on Ars Technica from August 15 2015. And the author of the blog on using it for that, mentions he got started as a reporter for a rag using one. I’d love to find a REX rig and its docking device, also any of the Psion ones.

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