People's Computer: Sinclair ZX81 - Computerphile

Clive Sinclair had a vision, an elegant, affordable computer. Sold as Timex 1000 in the US, the ZX81 was cheap and cheerful; for many programmers, their first rung on the ladder of computing.

This video was filmed and edited by Sean Riley.

[dunc]

As a software engineer named Jason, I declare this the greatest computer program ever written.

[mikedench]

What we tend to forget was the excitement this machine caused! YOU could write a useful little program that did something which would otherwise have been quite laborious or, of course, YOU could make a little game maybe like Pong! The power the ZX81 put at your command, that was the rush, that was what made me demonstrate it to friends at every opportunity. Now we have wonderful machines but we've lost control over them, they've become appliances rather than tools for the mind.

[richwickerman]

My first computer, now I am a lead developer all thanks to starting on a zx81

[neilwilson]

I had one (Thanks dad!!!) I did BASIC on it, played games, and was utterly blown away. My dad was an engineer, and saw this as a way to get his son into future tech. In 2025, I am still in IT, and so are my kids.

[RetroLindsay]

I loved the zx81 It was my first computer and I used it all the time trying to make a simple calculator game

[stephenguppy]

Oh, the joy of owning one of these. The touch-tone nature of the keys made it difficult to type and there was no sound, but this was cutting edge..

[p]

I loved my ZX81. I glued my ram pack to the back of the 81 which made it permanent, but 100 percent reliable. I wish Sinclair had added a sound function like a simple beeper, and also made a version with space for 16K on the motherboard though.

[thomas-ioh]

Oh how I remember my ZX81. It was my very first computer and I learned an awful lot from it in a rather short time. I did find a short ribbon cable that plugged into the back of the computer and the other end plugged into the 16K ram pack. That cured all the problems with the ram pack. I opened the case and modified the video output from a modulated signal to a composite signal. It was a very simple fix that took less than an hour to do. I did the modification so I could use the video monitor I purchased instead of the tv set. And the video output looked much better. I built a real foundation in programming in BASIC for myself with this computer. I still have my ZX81. It's in a sealed box. It might not ever work again but that's ok. I take it out of the box every once in a while and wow do the memories start rushing back to me.

[ericwright]

I built mine like so many. When powered on, the keys V G T 5 6 Y H B would not work. Made me very sad, but I did get the membrane keyboard replaced and I started my career in programming, and hobbying with electronics. Thank you Clive Sinclair.

[kumbah]

This is such a nice walk down memory lane, and the video that goes along with it, the one about RAM pack wobble ... just have classic written all over them. :)

[SirArthurStreebGreebling]

The ZX81 is the definition of efficient. I got a second hand one for Xmas in 1983 (I was 11) and it was the future. I spent hours programming it (when did it become 'coding'?) from Sinclair magazines. Trawling shops for games.Then Software Farm came along with 'hi'res' games. It really was brilliant. It proof to me that yes, thing have changed beyond comprehension, but we really do not need 1TB to run a computer. Great days. and the best thing was no moving parts, so when it got flung across the room in frustration, it didnt break.

[michaeldibb]

There's a Sharp MZ80K in the background! That was my second computer after the ZX81. Happy memories. :)

[AlexanderEsa]

Would love to see more longer videos from you guys demonstrating various programs on these retro computers

[MurrayPearson]

My father was an environmental engineer; it was on his ZX81, in the summer of 1981, on which I programmed my first video game. His machine was FANCY, it had a 64K(!!!) memory pack, which was so large that the CPU couldn't address it all! You had to use a POKE command to switch between the upper and lower 32K blocks. He used them as microcontrollers, a sort of early '80s Arduino: by attaching data acquisition and relay control cards, he made settling tank controllers for a mine in the Sierra Nevada mountains. He could buy them for $30 each in 1983, and nothing could touch that price point.

[jackleg]

Wow! Jason just described a part of my childhood perfectly!!

[dowekeller]

My first micro was the Timex Sinclair 1000 (essentially a ZX-81 with twice the RAM, a whole 2K). I don't recall having much trouble loading programs. The manual (the same as for the Zx-81), lots of example code, and ramped the difficulty up gradually. The keyboard was crap, but the way it let you press one or two keys rather than typing in an entire command or function name helped.

I have many fond memories of laying on the carpet, bathed in the glow of my tiny black and white TV, creating games, solving homework assignments, and running out of memory all the time.

[stvnnmnn]

This computer for me was my first graphing calculator. It wasn't marketed as such but it is very similar. With just a minor bit of BASIC, you could compute and graph functions. It was very helpful to me for math class.

[angladephil]

I started with it... and then worked for 35 years as a programmer, in a bank, in France.
Nice memories ...

[absinthedude]

I still have one, now with a modern SD card adaptor and 32K RAM pack that doesn't wobble. It is unfairly criticised. For the price, there was literally *nothing* else available. And it was the first computer to make it into regular shops when WH Smiths took what they saw as a gamble and agreed to stock it. Prior to that you had to find a specialist "computer hobbyist shop" or buy mail order from the back pages of electronics hobby magazines. The ZX81 went mainstream and you could toddle off to Smiths (later Boots and Dixon's) and buy one off the shelf....take it home, plug it into your existing TV and off you went. There are reasons beyond nostalgia why there is *still* new software and hardware being made for this little machine.

[hankmiller]

My first computer. After that the Vic-20, Commodore 64 and Ataris ST40. Years later I started my own IT company and got wealthy.
It all started by the ZX-81 and learning BASIC and Assembly on the Vic-20 (6502). Great times and great memories.