The bane of the single line display! It's amazing what constraints like that can do to your imagination and skills, though. You have to be very clever.
I programmed all day at school for years on the Casio version:
I had an MSX machine at home and a casio (not sure anymore which one although I still have it, somewhere, and last time I tried, it still worked but that's > 10 years ago); so in class I could write on the casio then, then copy to paper, delete, write more, copy to paper etc. And when boring af school was over, I would type into my MSX with the necessary changes to the BASIC code. Good times.