ZX81: my first ever computer

It comes to something when my first ever computer is on display in a museum. I guess that means I'm old. I first saw one in the Arts et Metiers in Paris 10 years ago but this one is behind glass in Manchester. I learned to programme Basic on this machine. The memory was 1kB and you stored programmes on cassette tapes. I never really got that to work. I found this old website https://www.cise.ufl.edu/~mssz/CompOrg/CDAintro.html which has a graph showing that the growth in computer memory size in the 1980s and 1990s was exponential. It makes predictions about what will happen in the Year 2000! I also found out about Moore's Law which is another exponential prediction: that the number of transistors in integrated circuits doubles every two years. This is at the heart of what it means to be exponential. You add a fixed amount to one variable (two years to time) and multiply the other variable by a factor.