I used to have a ZX81 and I wish I hadn’t got rid of it now. What an amazing little computer, and how much you could do with 1k of memory!
I’m glad to see that the ZX81 museum is a really well curated little site. I found quite a lot of stuff on there that I’ve had in the past.
These days I only have a ZX81 emulator on my Android phone. I must do some more bits and pieces with that soon.