Retro Reproduction Captures The Style Of The Sol-20

Sol-20 reproduction

In the early years of the computer revolution, a machine like the Sol-20 really stood out. Where most hobbyist machines had front panels that bristled with toggle switches and LEDs, the Sol-20 was a sleek, all-in-one that looked like an electric typewriter in a walnut-trimmed box. Unfortunately, it was also quite expensive, so not that many were sold. This makes them hard enough to find 40 years later that building his own reproduction Sol-20 is about the only way for [Michael Gardi] to have one of his own.

In a lot of ways, the Sol-20 anticipated many of the design elements that would come into play later. Like the Apple and Commodore machines that were coming down the pike, the Sol-20 was intended to be plug and play. [Mike] celebrates that design with a full-size reproduction of the original, concentrating on its unique aesthetic aspects. The reproduction mimics the striking blue case, with its acrylic front panel and walnut sides. The keyboard is also an exact match for the original, in looks if not in function — the capacitive mechanism proved too difficult to replicate, so he opted for a kit using Cherry switches and custom keycaps. [Mike] also used his proven technique for 3D-printing the memorable Sol-20 logo for the front panel, in the correct font and color.

Under the hood, a Raspberry Pi runs an 8080 emulator, which supports a range of virtual devices, including a cassette tape drive and the video output. For fun, [Mike] also imagined what a CRT display for the Sol-20 would have looked like, and added that to his build. It’s a great-looking machine that never was, and we appreciate the attention to detail. We’ve seen that before — his 2/3-scale VT-100 terminal comes to mind, as does his reproduction of a 1960s computer trainer.

26 thoughts on “Retro Reproduction Captures The Style Of The Sol-20

  1. Not many of any computer was sold at that point. Wikipedia says 10,000 were sold, that seems like a decent amount.

    The Sol was on the cover of Popular Electronics for July 1976 (overlapping the Cosmac Elf articles).. So it was still early, a small company sellling to a small market. It was more oike a comoact S-100 computer, the video card plugged in, I firget if the RAM was plugged in too.

    Apple, Commodore, and Radio Shack came a year later, which is a short time except when you’re living through it. They benefitted from watching early entries, and some evolution, so offered everything on one board. Two of those companies existed and were successful, Apple set their sights higher and got financial backing. There was bigger infrastructure, and a wider awareness of small computers.

    So I think the Sol sold pretty well. It can’t be compared to what happened later (but it did help buikd the foundation for later).

    Sphere had an all in one early, but it was never clear how many they sold, and “nobody” remembers that computer, so nobody says “it didn’t sell well”.

        1. It’s gotten way better in two years.

          But if I was nitpicking, it would be about what I said, not the typos. I was already nitpicking the premise that the Sol didn’t sell well. But I felt I was adding to the article, not just nitpicking. I slowly come to see that not everyone was around at the time, even though I remember buying one of the issues that included the Cosmac Elf that July, when the stores stayed open later than usual because the Olympics were in town

    1. As one of the two inventors of the original Sol-20, I salute you!! You’ve made a really cool replica.
      BTW – I donated the last two Sol units I had to the Computer History Museum in Sunnyvale, CA, as the power supplies finally gave out and I didn’t have the time or energy to rebuild them. I also had a Shugart 8″ HD attached using a SCSI controller, so I could run CP/M. I also have a possible still working PTC Helios Double 8″ floppy drive.

      also BTW – Sadly, the Smithsonian no longer has its large computer history exhibit where two Sol-20s were on display for many years.

      1. I think that the Sol-20 was one of the most beautiful computers from that era. I wanted one based on looks alone, but never ended up getting one. My first computer eventually was a used Apple ][.

  2. I took an hour drive to look at one of these back then. It was pretty attractive and had built in video? IIRC it was at least half the price of a new Ford Mustang. I eventually bought an AIM-65 ($375) in 1978, mostly due to expandability and the 6502 memory mapped I/O, excellent documentation, and multiple languages in ROMs, a thermal printer on the board, and a keyboard. Hard to beat!

  3. The first computer store in town had one for Purdue students to lust over. I remember seeing it in the store down the street from the food coop. Those zines are around here somewhere.

  4. Tell me it’s not a Pi. Tell me it’s not a Pi.

    Sigh. It’s a Pi.

    I mean, it’s great, having a bent-metal-with-hardwood-sides computer – that was a popular and distinctive packaging method, and I thought that the SOL and Ohio Scientific’s similar offering looked pretty cool at the time, but I’m sure that factor would wear off pretty quicly.

    1. Yeah, I figured it was a pi. Most of these retro recreations are. That flashy switchy computer that you often see on the bottom of the first page from the Tindie links is quite expensive, but it’s just a pi too. You’re paying for a box and an emulator with these things. But why complain? Just join the game:

      1. Find old nostalgic thing.
      2. Make a lookalike case cheaply.
      3. Stick a pi in it.
      4. Profit!

      1. Yeah, I really don’t have all that much room to talk, since I’ve got a project in the works to do a Pi 4 in a Toshiba 1100 form-factor. But that’s really just coincidence; it’s not that I’m trying to make something that looks like an 1100, but that with the size and center-of-gravity constraints, it just keeps ending up that way.

        And I do understand. The Pi computers just make everything easy, and a whole ecosystem has grown up around them. It used to be hard to find TFT displays without going to the dark side (i.e., Ali Express and its ilk), but now you can find them on Amazon, and have them delivered overnight. So it works to my benefit every way I look at it.

    2. I had, still have, an OSI Superboard, which was what was in the C1P. It was fine 40 years ago, though I can’t remember where I placed the monitor. But I used it for nothing more than entering or writing programs. It’s deep, and it really can”t be adjusted much. Of course, the same could be said of the Apple II.

      The Sol is not particularly complicated. An 8085 and dense static RAM would give most of it. Some sort of keyboard interface, and the stuff to drive the s-100 bus. Some sort of video interface, the Sol-20 ” cheated” by using the Processor Technology VDM-1 board.

      How much emulation do you need? I doubt people are going to run software written for the Sol, so it looks like a Sol may be all that counts. At which point the hardware could be closer to 1976.

        1. Your recreation looks very nice! It’s clearly visible that you put your heart into it. Also, it looks morw or less like a 1:1 size replica. Other people mainly do miniatures. So that’s a plus here, too.

          Personally, I think it’s well done. Kudos. 😎

          *If* I had anything to complain, it would be the lack of metal for RF shielding. However, since about no one today cares anymore and since this is a personal, non-commercial project, too, I think that’s a non-issue here. Also, there’s technically metal paint available online that could be sprayed to the inside of the chassis, if really needed..

  5. Byte Shop, Tucson, AZ. Got a bag of chips, huge pcb, sockets, wood and iron case and keyboard. Thought there had to be at least one bad chip in there, nope. Took a couple days soldering and it was a beauty, up and running with cassette deck, B&W security monitor. Eight months later and another grande$, I had an S-100 buss Shugart 8″ drive. A lot of fixin’ Motorola two-way radios for a measley 200K(?) of storage, punch a notch in the corner and double your space.. The Sol was running CP/M and MBasic, Electric Pencil. Sold the whole thing much later for $100. Interesting times..

  6. In Toronto in 1977 I worked at the Computer Place on Queen St.
    I was 15 years old and my job was to assemble parts kits to make, then new, home computers.
    One of those computers was the SOL-20. If I recall correctly I had to solder 128 separate
    ICs into each of them. I do not recall how many I assembled but I got quite good at it by the end.
    I also assembled IMSAI 8080s and Zytan’s.

    I now have a mess of old laptops, arduinos, two Raspberry Pi’s and a Lenovo desktop.

    The Good Ol’ Days.

  7. I bought my SOL-20 from a store in West Warwick, RI. The sales slip is still around here somewhere. The 32K model was something like $1350 and an additional 16K was $395. At that time a Pinto, Vega or Gremlin was right around $2000. It also had a Computalker speech synthesis board, and I wrote a text-to-speech program in ALS-8 assembler. In the early ’80s I donated the system to Western Carolina University. Ah, the good old days…

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