I got a 2400bps modem to hook up to my C64 and was a bit unhappy that I would get all kinds of errors when receiving data from BBSs, and I figured out that the

I got a 2400bps modem to hook up to my C64 and was a bit unhappy that I would get all kinds of errors when receiving data from BBSs, and I figured out that the C64's native serial port code was too slow, it was dropping bits. I was using CCGMS terminal program at the time so I figured out how to hack CCGMS and wrote my own bit-banged serial I/O code in assembly language and that fixed the problem up nicely.