Aprotek sold a 2400 baud modem that worked just fine on the C64 without any problems.
Aprotek also sold an RS-232 interface and with that, a US Robotics modem, and a copy of Novaterm64 you could get 4800 baud on a C64. No, it didn't shut off the screen.
And if you had a 128 and a copy of Desterm, you could even get 9600 baud! But you had to have an 80 column screen and put the CPU into Fast Mode (which DOES disable the VIC II) to do it.
Biting the hand that feeds IT
