ZX81 #atozchallenge

Almost done here!

In the early days of microcomputing, machines were really expensive. Pretty much the least expensive computer you could get in the US was the Radio Shack TRS-80 (affectionately known as the “Trash 80”), which cost $600 ($2500 in 2018 dollars) and that was just for the computer, which came with 4 KB of memory, a 64-line monitor, and a keyboard. I don’t even think it had a disk drive (although I can’t imagine it didn’t), but you could add on floppy disk drives, hard drives, tape backup, more memory, and other peripherals, all available from Radio Shack. The TRS-80 came out in 1977 and quickly dominated the market.

Pretty soon, just about everyone and his brother had a computer of some kind. All, of course, except me. I couldn’t justify spending that much money on something that was basically a toy that I knew I’d be on all the time. So I did without.

Until I heard about the Sinclair ZX81.

The Sinclair ZX81, pretty close to full size. Evan-Amos [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)%5D

The ZX81 came with a whopping 1 KB of memory, but a 16 KB memory expansion (pretty much a sine qua non if you wanted to do anything besides write a program that spit out “HELLO WORLD”) was available. Storage was supplied by your own cassette recorder, while the monitor was your own black-and-white TV. It was delivered with a version of BASIC loaded on it so you could write programs to do stuff. I made my case to Mary, and $80 later, I was the proud owner of a ZX81 (which I soon learned was pronounced “ZED-X-81”).

I have to say, for a little computer, you could write some pretty interesting stuff on it. First thing I did was to type in some programs that I found in a couple of books we found at Crown Books. I had to get used to the way you typed in the various BASIC commands, which was not to type them, but to press one of the keys that would type the whole command out for you. I also had to learn how to adapt the programs in the books (written for the TRS-80) so they would run on the ZX81. Once I had done that, though, I was in business. I actually designed and wrote a program to balance the checkbook that worked pretty well, and I was quite proud of myself.

The ZX81 had almost cult status. There were magazines that talked about new software that was available (on cassette) and how to get the most out of the machine, and I started reading them. Another guy at work had one, and we’d talk about what we had done and what we had found out, we’d share magazine articles… I mean, it was great!

For about nine months, anyway. After about that long, I had gotten tired of it. Setting it up was a drag, trying to keep one of my cats from chewing through the power cord became a hassle (as did soldering the wires back together), and, let’s face it, it was an $80 computer that was pretty severely limited in what it could do. Timex, the company that owned Sinclair, started marketing the computers under its own name (the Timex-Sinclair 1000), but it was pretty much the same little computer that I had grown tired of.

Then, it just sort of vanished. The magazines were gone, the books, the software, the computers themselves, all gone, pretty much overnight. It was time to move on.

And that, my friends old and new, is that for the 2019 Blogging from A to Z April challenge. I hope you’ve enjoyed it, whether you’re a participant or just someone who dropped by to read. Watch the Challenge blog for further updates.

28 thoughts on “ZX81 #atozchallenge

  1. My best friend had one. He showed it to me the day he got it, but he never even set it up, proclaiming it to be too much trouble. 16kb of memory – amazing what you could do with that.


    1. 16K is nothing now. It really wasn’t much then, either, come to think of it. And the amount of setup you needed to do is part of the reason I decided that maybe it was more trouble than it was worth. It was fun to play with, though…

      Liked by 1 person

      1. I had a programmable calculator that had 512 bytes of working memory. You could partition it into registers or commands. Each command took 8 bytes. I actually prototyped specifications for an inventory management system on that thing. I was writing down lots of intermediate values, but once you got into he process, we were able to test the design on over 100 inventory items to prove that the various features worked.


        1. Where there’s a will, there’s a way. A guy I worked with turned one of those calculators into a synthesizer. Took him most of an evening (we worked third shift, so the place wasn’t crawling with big shots).

          Liked by 1 person

  2. Don’t know much at all about computers. My son-in-law Kevin is my advisor. I just recently got rid of all my old computer stuff; towers, keyboards, wires, monitors, etc. Learned how to remove hard drives on YouTube. Kevin recommended a Chrome book which I bought for $500. Kevin said it is the latest technology and will last me about 3 years – WHAT! I was thinking more like 20 years!


      1. “Forget what it was doing half the time,” is a good way of describing our “old” IPad and Fire2. Planned obsolescence for sure.


        1. The Fire tablets are great for about one year, then they really slow down and are practically unusable, even for reading.

          Mary’s old iPad had 16GB of storage on it, and it was always full. When we got her a new one, I told her she should get one with twice as much (32GB). She came home and told me the smallest they were making anymore was 64GB. Guess they figured no one could live without that much storage, and the more I think about it, they’re right.


  3. John,

    I don’t remember it but what a hoot! Today’s smartphones are like supercomputers compared to yesterday’s technology. Of course, I say that all the time when I think about even some of the first PC from the early 80s. It’s amazing how electronics have evolved over the past four decades. It’s been great sharing with you and reading your fun posts. Congratulations on finishing another A2Z year!

    A2Z Little Mermaid art sketch ‘Zeus’


    1. Smartphones can do more than any computer I worked on in school and probably half the computers I encountered in the working world. They can do stuff I only dreamed of…

      It was a blast! Thanks for making this a fun year.


  4. Was not at all familiar with this little gadget. LOL about your mini-Mac forgetting what it was doing. Congrats on finishing the A to Z but of course with you I had no doubt.


  5. When I saw the title of today’s post, I thought it was going to be about a car, maybe a cousin to 240Z, 280ZX, or Z28… Computers, though… that’s a whole different “drive”.

    You have such interesting themes for the A to Z Challenge each year! I enjoy reading your posts.


  6. This reminds me–somewhere in my garage I think I have an old Radio Shack computer that used to be my uncle’s. Another thing I need to get rid of.

    Another Challenge mostly behind us. The A to Z Team of 2019 has been exceptional!

    Arlee Bird
    Tossing It Out


  7. So the letter Z was pronounced the correct way..heehee. See is the only way…hahahaaa…they must have been Canadian whoever invented it or named it. I don’t even remember this contraption. Congrats on finishing the A to Z


  8. Well John, we made it! Woo Hoo CONGRATS! So for Z hmmmm I never heard of one personally. I’ve never heard anyone even talk about them. Sheesh I must be hanging out with the wrong people I guess! hahahaha But what I do know is CONGRATS on finishing our A to Z!


  9. Technology does get outdated very fast. I still have some of the old Floppy Discs. Now even CDs are said to be an ‘old fashioned’ way to store data – mostly photos or music for me. Sigh… Congratulations on the AtoZ!


    1. Thanks! You too!

      I ripped all my CD’s to mp3 years ago, and even managed to convert a few cassettes. I hardly listen to them, what with all the streaming services.


  10. Never heard of these. Guess I missed it entirely! Technology does move speedily these last 20-30 years… Reminds me of pagers and mp3 toys my kids had and palm pilots — so much stuff all the rage, all hyped up and then Poof! Gone!


  11. Congrats on finishing the A to Z (did I have any doubt? No, I didn’t). I need to do a post on old computers one day – not with your knowledge but from the viewpoint of my son (late 20’s) who has a fascination for some of this archaic equipment.


    1. The funny thing is, the TRS-80 and the ZX81 represented a big move in the path to today’s smartphones, tablets and notebooks. What you tuck into your pocket now is hundreds of times more powerful than the machines I started on in the ’70’s. I have 3.5 terabytes (3.5 trillion bytes) of disk storage on my desk; you needed something the size of an Amazon warehouse filled with disk devices to have that much storage as recently as 30 years ago. It’s amazing.


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