The C64 can output composite video natively (with the yellow, red, white cables). You could buy or build yourself such a cable and then use an composite to hdmi converter box to use your modern monitor. Although I do not know if cheap ones will work with the signal, you have to do some more research on that.
The C64 can output composite video natively (with the yellow, red, white cables). You could buy or build yourself such a cable and then use an composite to hdmi converter box to use your modern monitor. Although I do not know if cheap ones will work with the signal, you have to do some more research on that.