Power Supply Connector

From C64-Wiki
Jump to navigationJump to search
Power supply and power switch of the C64

The C64 is powered through the power supply connector. The connector of the external power supply must only be plugged in this connector. The power supply provides 5 volt direct current (DC) and 9 volt alternating current (AC). The power supply connector is located next to the power switch and is labeled as CN7 on the motherboard.

Contact assignment[edit | edit source]

The power supply connector is a 7 pin DIN connector (DIN 45329).

Contact assignment (female)

Pin Voltage Current Comment
1 GND N/A Ground/Not connected
2 GND N/A Ground
3 GND N/A Ground/Not connected
4 - N/A 5V or Not connected
5 + 5V DC 1.5 A 5 Volt direct current
6 9V AC1 1.0 A 9 Volt alternating current phase 1
7 9V AC2 1.0 A 9 Volt alternating current phase 2


It should be possible to load the 5 Volt of the external power supply with at least 1.5 Ampere.

The 9 Volt alternating current (AC) is the reference frequency for the internal clock and - after being rectified - it is used to power the SID chip (9 or 12 Volts), partially also the old version (NMOS) of the VIC-II chip as well as the motor of the Datasette (6 Volts).

The pin assignment has been thoroughly checked (pin 1 is between pin 4 and 6, pin 3 is between pin 5 and 7). You can find different assignments on the internet which are just completely wrong. Nevertheless, we cannot warrant the correctness. The inversion of pin 6 and 7 would have no consequences in case of the alternating current, as well as the inversion of pin 4 (unused) and pin 5 (5 Volt) will only cut the C64 from the current supply if you have the motherboard without these linked (all PCASSY before and including 250407-RevA). If you build your own power supply or if you repair a power supply cable, it is recommended to check everything twice, for "nothing dies as silently as a microprocessor."