ZX81 - a short video of failure

In this remarkably short video (for me) I take a look at an eBay purchase from 15 or so years ago.
Will it work?
Well, that entirely depends on your definition of work. Certainly there's power on board and the 7805 regulator gets toasty!

[@JazzmansHardware]

Whoa, TH-cam somehow recommended the video to me. Looking great, keep up your work no matter what! I used to play a lot of Sinclair in post-soviet Russia in the early 90s.

[@stevesretroloft]

Thank you Jazzman :)

[@stevejohnson1321]

I had the newer version, which got named "timex sinclair" stateside. Because I couldn't fathom what a user group was, I would type programs in manually. Sometimes they would work, other times not..Probably I returned the computer for credit, but the cassette recorder is still in my bedroom. Today I run Ubuntu -- someone else writes the applications!

[@westleygress2160]

This was my first computer back in the late 70s.

[@stevesretroloft]

I think for many of us it was our first computer.

[@PartarioAbdullah-Levi]

Surely you mean early 80s? The ZX81 came out in 1981 (hence the name).

[@jimenglish1981]

Thanks for trying at least!!! I enjoyed your efforts!!

[@stevesretroloft]

I managed to find a circuit diagram, so it might live again.

[@perrymcclusky4695]

My first computer was a variation of your model. It was a Timex Sinclair 1000. I also had a 16k memory expansion pack. Back in the mid-1980’s it was fascinating to have. Happy that you tried to bring that one back to life.

[@stevesretroloft]

I do have a 16k expansion somewhere in the loft, so I'm ready for some games if I can get it working in the future (assume the 16 ram pack also works!)

[@perrymcclusky4695]

@@stevesretroloft it was my Timex Sinclair 1000 that got me fascinated with small computers. That minimalistic board was incredible. Likewise, today I find the Raspberry Pi Zero models similarly fascinating. Best wishes with the ZX81.

[@truthseeker2275]

Put it in the fridge...it is what I used to do when it got hot.

[@stevesretroloft]

I can't recall my original one getting this hot. Although my school friend commented (at the time) about warming hands on his ZX81 in the winter - so maybe they did!

[@truthseeker2275]

@@stevesretroloft I used to spend all my time on it - like 12 to 16 hours a day...I did things like making bit map graphics by manipulating the ALU in assembly. I made RF transmitters by toggling pins on the expansion connector with a piece of wire connected...fun times :)Today I am an embedded developer...pretty much the same job :) still fun times.

[@WoodyGamesUK]

OMG I had the same joystick, with the two yellow buttons!

[@stevesretroloft]

The Zip Stick was quite popular at the time, I seem to have collected a few over the years!

[@WoodyGamesUK]

@@stevesretroloft My first choice was the albatros though (that one I remember the name)

[@InfiniteLoop]

I had one of the US versions of the zx81 with the 16k brick that fell off the back,at one time, and yes it was pathetic, but I sincerely miss it and wish I still had it even if it was just to sit on the shelf.

[@stevesretroloft]

The wobbly RamPack was a feature! I originally had a memo tech ram pack that was contoured to the ZX81 so it was much better. With regards to the computer it was a basic device, but probably cheap enough to get the masses (certainly in UK) to try it/

[@TheBasementChannel]

If you don’t have a go, you’ll never know!

[@stevesretroloft]

I'm determined to fix it (if possible), so there might be a part 2 at some point.

[@AndrewS2972]

No that's probably not a good idea

[@baxtardboy]

Display it on a shelf with pride mate. Get a wee cheap phone stand for it.

[@stevesretroloft]

It might end up that way to be honest. It's getting close to being triggers broom if I change any more components!

[@givenfirstnamefamilyfirstn3935]

Tuning in the TV would help.

[@stevesretroloft]

I've tried that, I don't think it's even getting that far to be honest.

[@joeynrg]

I built one of these but with composite video, if you want me to have a look at it, I don't mind. I'm a technician at a computer shop if that makes you more comfortable me looking at it?

[@stevesretroloft]

To be honest it's probably much easier to pick up another one rather than the hassle of shipping it around for repairs. There's probably not too much more to with it other than changing some the IC's which can be a pain to obtain (Certainly the ULA is a difficult one to find).

[@wonderboy7768]

haha the thing was tedious when new

[@stevesretroloft]

Looking back they weren't great, but it was cheap and with that I guess it met Sinclair's mantra of getting it out to as many people as he could.

[@MarkJones-gt2qd]

It was wonderful. After the ZX80. We had little else at the time remember. Plus many many games. We couldn't all afford a vic 20. I wanted an Atari 800 but I was a penniless student.