The first 'home' computer I saw operational was a ZX80, a colleague purchased it in kit form and put it together (he had had some experience with sinclair products as he had built his match box radio and an audio amplifer). The following year the ZX81 was introduced, again I didn't purchase I relied on my colleagues for that ( was way outside my means), I just borrowed it from time to time.

As most people who have used the ZX81 will know it was time consuming programming the little machine and just when you think you have a neat program the power fails and all is was 16x worse with the RAM pack!!.

The one and only program I had patience to write on the ZX81 was Hangman, it work fairly well but had a limited vocabulary.

16K RAM Pack
16K RAM pack inside