Blog o' Tiggs

Still have mine, put away somewhere. I also learned to program in BASIC on this machine. Since I'd had some experience in electronic construction, I ordered the kit version. Figured I'd save some money soldering and screwing it together myself. They sent the ready-to-use version instead, but didn't charge me the extra $20.

Using that membrane keyboard was quite a challenge! I devised a method to make typing on it more efficient, wrote this up as an article for a little magazine for ZX 81 users. All it amounted to, really, was pressing down on the keys and drawing your finger across it. It made a little squeak or pop from friction. This made the key action more reliable.

Timex and Sinclair were working together at around the time I got my machine, so they began calling it the Timex-Sinclair 1000. It was only slightly modified from the original ZX 81.  2 K of RAM, with modules available that plugged into the back to increase this to 16 K RAM. I remember writing a program to test reaction time in response to an audio tone. Also tried to program it as an accurate stopwatch-like timer, but never quite succeeded. 

Interesting to realize that the computers used by the United States Air Force in the 1950s were also limited to 2 K of RAM. They probably filled a room, though!   

Edited March 14, 2019 by bison

A "Chisel sensitive keyboard", as my Dad used to call it.

My best memory of that ZX81 was taking turns with my Dad and my Brother to type in an adventure game from a magazine.

We each typed a few lines, then switched, so no-one had to read all the code, so we could still all play it together, afterwards.

Can't remember the game at all. Just happy memories of the three of us, building something together.

I missed out on the ZX81. My first computer was a ZX Spectrum... colour and with a massive 16k memory (upgradable to a whole 48k).

7 hours ago, Waspie_Dwarf said:

I missed out on the ZX81. My first computer was a ZX Spectrum... colour and with a massive 16k memory (upgradable to a whole 48k).

Same, I grew up on the ZX Spectrum 48k (and later the 128k), as well as the Commodore 64.

2 hours ago, Saru said:

Same, I grew up on the ZX Spectrum 48k (and later the 128k), as well as the Commodore 64.

I coverted my friend's BBC computer... especially when he introduced me to Elite.

So you had to connect it to an external monitor (not provided)?

I had to double check with my brother, our first family computer was the Atari 400.

9 hours ago, Vlad the Mighty said:

So you had to connect it to an external monitor (not provided)?

No monitor was provided with the ZX 81. It was connected to one's television receiver, via a cable, and RF modulator.