Find below many schematics of the Commodore 64. There are many variations of the console so the schematics may not be accurate to your specific version.

Commodore 64 Schematic 1



Commodore 64 Schematic 2



Identifying Ports

Commodore 64 Ports



Components

U1: CIA 6526 (Keyboard & Joystick Controller) U2: CIA 6526 (Serial Bus / User Port Controller) U3: 2364 (Basic ROM) U4: 2364 (Kernal ROM) U5: 2364 (Character ROM) U6: 2114L-30 (Color RAM) U7: 6510 (MPU) U8: 7406 (Hex Inverter Buffer) U9: 4164 (DRAM 64Kb: 64K x 1-bit) U10: 4164 (DRAM 64Kb: 64K x 1-bit) U11: 4164 (DRAM 64Kb: 64K x 1-bit) U12: 4164 (DRAM 64Kb: 64K x 1-bit) U13: 74LS257 (Quad 2-Data Selectors/Multiplexer) U14: 74LS258 (Quad 2 To 1 Data Selectors/Multiplexer) U15: 74LS139 (Dual 2 To 4 Line Decoder/Demultiplexer) U16: 4066 (CMOS Quad Bilateral Analog Switch) U17: 82S100 (PLA) U18: 6581 (SID) U19: 6567 (VIC II) U20: LM556 (Dual 555 Timer) U21: 4164 (DRAM 64Kb: 64K x 1-bit) U22: 4164 (DRAM 64Kb: 64K x 1-bit) U23: 4164 (DRAM 64Kb: 64K x 1-bit) U24: 4164 (DRAM 64Kb: 64K x 1-bit) U25: 74LS257 (Quad 2-Data Selectors/Multiplexer) U26: 74LS373 (Octal D-Type Flip-Flop) U27: 74LS08 (Quad 2-Input AND Gate) U28: 4066 (CMOS Quad Bilateral Analog Switch) U29: 74LS74 (Dual D-Type Flip-Flop) U30: 74LS193 (Binary Up/Down Counter with Clear) U31: 74LS629 (Voltage Controlled Oscillator) U32: MC4044 (Phase Frequency Detector)