Commodore 64 Hardware Details
Introduction September 2020

This page collects all the schematics and datasheets for the Commodore 64 in one place--not just for the machine as a whole, but for every individual chip (including variants from multiple vendors in some cases). The goal is to gather in one place all the information I need for writing my own C64 emulator. Because there are several variants of the C64, but I need a complete and consistent picture of how all the components work together, this document focuses specifically on the Assembly 250407, Schematic 251138 version.

Commodore 64

Information on the system as a whole:

Assembly 250407

C64Wiki has information on the various motherboard revisions. This section collects key information on the 250407:

Component Index

Every IC on the 250407, with its PCB Identifier and a link to the section with details and datasheets for that component.

PCB IdentifierComponent
U1 Complex Interface Adapter (CIA)
U2 Complex Interface Adapter (CIA)
U4 Kernal ROM
U5 Character ROM
U6 Color RAM
U7 6510 CPU
U8 Hex Inverter
U9 Dynamic RAM (DRAM)
U10Dynamic RAM (DRAM)
U11Dynamic RAM (DRAM)
U12Dynamic RAM (DRAM)
U1374LS257 Multiplexor
U1474LS258 Multiplexor
U1574LS139 Demultiplexor
U164066 Quad Bilateral Switch
U17Programmable Logic Array (PLA)
U18Sound Interface Device (SID)
U19Video Interface Chip (VIC-II)
U20556 Dual Timer
U21Dynamic RAM (DRAM)
U22Dynamic RAM (DRAM)
U23Dynamic RAM (DRAM)
U24Dynamic RAM (DRAM)
U2574LS257 Multiplexor
U2674LS373 Octal Latch
U2774LS08 Quad AND Gate
U284066 Quad Bilateral Switch
U2974LS74 Divider
U3074LS193 Binary Counter
U3174LS629 Oscillator
U32MC4044 Phase Detector
Complex Interface Adapter (CIA)
Kernal ROM
Character ROM
Color RAM
6510 CPU
Hex Inverter
Dynamic RAM (DRAM)
74LS257 Multiplexor
74LS258 Multiplexor
74LS139 Demultiplexor
4066 Quad Bilateral Switch
Programmable Logic Array (PLA)
Sound Interface Device (SID)
Video Interface Chip (VIC-II)
556 Dual Timer
74LS373 Octal Latch
74LS08 Quad AND Gate
74LS74 Divider
74LS193 Binary Counter
74LS629 Oscillator
MC4044 Phase Detector