They've been around for a while I guess, how else could have they ripped the disks and tapes for emulators, if not by such cables?
@TC: You should try implementing other hacks on your C64, like chatting on IRC, playing a video, playing ".mp3" files, etc.
One of my friends claimed he had a C64 which could control a microwave oven.
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Reverend Preacherbot: Wretched sinner unit! The path to Robot Heaven lies here, in the Good Book 3.0.
Bender: Hey. Do I preach at you when you're lying stoned in the gutter? No!