They’re both DE-9 connectors, but the C64 joystick port is not serial. Each direction on the stick and the fire button are connected to one of the pins on the connector, and a when direction (or the fire button) is pressed that pin has a voltage applied. So effectively it’s a parallel connection.
In a serial connection one of the pins is “send” pin and another is “receive”. The device then sends data as a bitstream over those two 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.
Wasn’t the C64 joystick port serial? Or has 40 years muddled it?
They’re both DE-9 connectors, but the C64 joystick port is not serial. Each direction on the stick and the fire button are connected to one of the pins on the connector, and a when direction (or the fire button) is pressed that pin has a voltage applied. So effectively it’s a parallel connection.
In a serial connection one of the pins is “send” pin and another is “receive”. The device then sends data as a bitstream over those two 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.