Who of you here, had one of these?

We here in NZ, used to refer to them as "The Wedge" - implying that their only real use, was as a door wedge.

I am sure that also was the case in other countries, and may in fact, have been borrowed from the UK!

A remarkable machine, that could basically do nothing at all with it's whole 1k of RAM.

ZX81....

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Smoke makes things work. When the smoke gets out, it stops!

1k ram was an upgrade for my mini-scamp computer. All of 256 bytes of ram, data entered by manually setting address and data toggle switches and output consisting of 8 leds.
But hey, they sold plenty and got people started on a career.

From today's perspective, it all sounds ridiculous and the hardware is junk, but the ZX 81 was essentially the first computer that a working-class person with an average income could afford.
Back then, most people would look at me pityingly and ask, “What on earth are you supposed to do with that?”, as if today someone were saying, “I don't have a cell phone.”

Not only did I use one, I still have it. In fact, I have several that I've been given over the years. :)  I still think it was probably one of the best computers ever made when you put it into the correct context. Yes, lots of compromises were made to get it to the right price point, but that doesn't matter when you remember that there was no alternative with the same capabilities that could be afforded by most families, never mind kids.

Sinclair BASIC was brilliant and definitely usable with the Sinclair keyboard, where all the common commands were laid out in front of you. When you put those together with the brilliant manual it was a great package and people could write reasonable programs from day one. You can't say that about any other system apart from the Speccy (of which I also have a couple).

Having 1k of RAM was enough to get you going. If the interest remained then adding the 16k RAM pack became necessary, but as a starter it was fine. Having 16k from the start would have put the system price too high. It was critical to hit £99.99 or lower because anything over £100 would have been perceived as too expensive at that time.

I had the 16k expansion. The connector was a source of much cursing.

Jim

  Mixtel90 said  

put those together with the brilliant manual it was a great package and people could write reasonable programs from day one.

I couldn't agree more. I learnt BASIC step by step using the well-structured manual (in German translation).
I was also able to brush up on the English I’d learnt at school by reading magazines such as *Your Computer*.
Edited 2026-03-28 19:01 by Martin H.

Here in the US, I had the Timex Sinclair 1000 with a 16K add-on. I didn't find it useless. It was a challenge. I did my first. Machine language programming with Peaks and pokes, and Learned a lot about the Z80 processor, More so than when I had TRS 80  model I. Like everything else, its limitations forced you to learn new things to try to do something with it.

Shai-Hulud? Way too many really hot Vindaloos then?  ;)

Yep, I had a TRS-80 Model 1 Level II too. :)  It was a pretty expensive machine over here, especially when you got the expansion interface too. I cheated on the floppy drives and got much cheaper ones from elsewhere. That's the system where I *really* lost sleep, spending way too many hours playing Colossal Cave and Zork. :)  I also learned quite a bit about the floppy file systems. All a bit useless now. lol

The zx-81 was my first home computer. I bought the kit version for $99 when it first came out. I upgraded the memory , the keyboard to full travel with an old TI-99 surplus from RadioShack. I have a version now made from pico with lcd screen and all the software I could find online. It still lives but not used as much.

I built a CNC TAIG Micro Lathe using Slo-Syn SS25 motors controlled by Cybernetic Micro Systems CY512 Intelligent Stepper Motor Controllers that required an 8 bit parallel bus with handshaking. My Altair 8800 was initially used with an ADM-3A terminal but the metal shavings were a nightmare. The ZX81 was perfect as the membrane keyboard loved greasy fingers and debris. The CY512 would operate in direct mode with immediate commands like Rate 200, At home, N 1000, + ccw, Go, and the motor would move 5 revolutions at 200 steps per rev.

Learning Z80A machine code on top of 8080 (Altair, Prompt80), 8085 (SDK-85, Pro-Log 8085), 8748/49 (Prompt 48), 8051 (SDK 51), Z8BASIC (home built), PIC16, SC/MP was instrumental in my getting a programming job a few blocks away (by bike) for an Hitachi HD64180 Z80 clone (the aircraft carrier).
Edited 2026-03-30 04:01 by barewires

First there was Startrek TOS running on German TV and years later the ZX81 where I spend hours in front of flickering TV.
But then the great C64

@barewires
My respect, what you describe is high end engineering for that time!

I go back a little further than the ZX81 - I had a brand new, just released, Sharp MZ80K given to me as a present from a wealthy relative back in 1978 - together with a dot matrix printer.  Wow, was that an introduction to computing.  Built-in CRT monitor and a tape deck that took cassette tapes to record programs, data and so forth.  In fact, I still have the machine stored away somewhere in one of the outbuildings; I am minded to search it out and see if I can get it working.  After that, I was given one of the first IBM PCs and then the first IBM Laptop - the IBM PC Convertible, in 1986.  I actually did dig out the IBM PC Convertible last year and it still works!  (I was a very spoilt kid!).