Oh man, the membrane keyboard. Now, did you save your files to cassette or did you have the Atari disk drive? The Atari 800 was a very decent machine. I remember having to translate some statements into Apple Basic on the ][+ and getting confused trying to debug things after running renum when then line numbers no longer matched what was in the book.
Cassette of course! If I remember correctly, it took 30 minutes to load programs I had written. Maybe it just seemed that long to me, or maybe that was the write times.
I was so happy when I saved up enough money to buy an Indus floppy drive. It was heaven compared to the damn 410. I still cannot believe how much typing I did on the Atari 400's keyboard.