I did a similar thing with the ROM of the VIC-20. I didn't have a printer though. So I wrote out the entire BASIC ROM in 6502 assembly language, longhand, in my

I did a similar thing with the ROM of the VIC-20. I didn't have a printer though. So I wrote out the entire BASIC ROM in 6502 assembly language, longhand, in my school exercise books starting from the empty pages at the back... My greatest sense of accomplishment came from figuring out how floating point arithmetic worked in an 8-bit processor, and then the sin, cos and tan functions.