No, the C64 (and other computers of the time) used a DSUB9 for the joystick connector. Top row 1-5: Up, Down, Left, Right, PaddleB; bottom row 6-9: Fire, +5V, GND, PaddleA. This was the common layout across all systems back then. The DSUB15 analog joystick port was later. And no, it was no serial port, just raw IO pins.
No, the C64 (and other computers of the time) used a DSUB9 for the joystick connector. Top row 1-5: Up, Down, Left, Right, PaddleB; bottom row 6-9: Fire, +5V, GND, PaddleA. This was the common layout across all systems back then. The DSUB15 analog joystick port was later. And no, it was no serial port, just raw IO pins.