[I know this is not exactly cutting each tech but as I spent some time finding a solution for my ZX81 problem I thought I would post it here for future reference]

I recently picked up an old Sinclair ZX81 computer which back in the 80’s was the very first computer I even owned.  I got it as a Christmas present either in 81 or 82 (I can’t remember exactly).  So with a 31 year old components there are bound to be some issues with it.

The ZX81 I picked up had about a 3rd of the keys on the membrane keyboard not working so I took the case apart and could see a break in one of the ribbons that connected the keyboard to the main board. The ribbon isn’t like the ribbons you see in modern PCs its more like tracing paper just a little thicker and about as strong!


My first thought was to see if I could swap out the keyboard and there are brand new ones available to buy but obviously they are not original and the membrane keyboard is actual stuck down to the case on the ZX81 and putting a new one on would never be as good as the original.

It turns out that all you need is a pair of scissors to fix it, the ribbon is very thin and can easily cut with a knife or scissors and so I trimmed the ribbon back to before the point of the break, cut the width to the right size of the connector and then it was ready to go back in the computer.


It was then a little tricky to get the other ribbon cable back in to the board which wasn’t actually broken but was cracked and I couldn’t get enough pressure on it to plug it back in so in the end I made a new edge with the scissors on that ribbon and I could then plug both ribbons back in to the connector. It’s a little tricky to get back as the ribbon is so thin I was frightening of breaking it and having to cut it again.


In the end I got them both back in, powered up the ZX and the keyboard now works fine.  I can’t see me doing a lot of programming on it but it’s great to get a little bit of computing (and my own history) working. Now to look for a 16kb RAM pack on ebay!



My working ZX81 next to it’s younger brother the ZX Spectrum 48K





2 thoughts on “Retro Tip: Fixing a keyboard on a ZX81”
  1. Wow – that brings back memories. The ZX81 was also my first computer and the one I learnt basic on.

    Its always annoyed me that whenever people talk about the start of home computing they always mention the ZX Spectrum but hardly ever seem to mention the ZX81. It was where things started for a lot of us.

    Wobbly 16K RAM pack?

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