N64:Video Output Notes

By default, the N64 outputs RF via a RF modulator, and composite and S-Video through the AV output port. There are various mods to add RGB or HDMI output.

RGB
Only a few revisions of the N64 have CSYNC already run to the multi-out and compatibility isn't consistent. If CSYNC isn't required, you can use a cable that gets sync from luma (pin 7) or composite video (pin 9) on the multi-out connector (luma recommended). If CSYNC is required, you can do an RGB mod that includes a proper sync signal as part of the mod, such as Voultar's N64 RGB board. Performing a mod like this one will allow you to use an NTSC SNES RGB cable that uses CSYNC.