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.
Information on the system as a whole:
- Service Manual Sep 1985 (block diagram, circuit theory, pinouts, schematics)
- Service Manual March 1992(better scans)
- Programmers Reference Guide 1983
- Clock timing details: dustlayer
- 6502 datasheet shows Φ0, Φ1, Φ2 timing relationships.
C64Wiki has information on the various motherboard revisions. This section collects key information on the 250407:
- My own machines, three revisions Photo 1 Photo 2 Photo 3
- Schematic from the Service Manual Page 1 Page 2
- (Buggy) Schematic by Carsten Jensen based on the Programmers Manual
Page 1
Page 2
This is much more readable than the schematic from the Service Manual but has errors including:- U13 pin 15 and 16 connections incorrect
Every IC on the 250407, with its PCB Identifier and a link to the section with details and datasheets for that component.
- Printed name: "MOS 6526"
- Datasheet (Nov 1981)
- Datasheet (recreated)
- More info: C64Wiki Wikipedia
- 8KiB ROM, provides the machine code implementation of BASIC.
- Printed name: "MOS 901226-01" or similar.
- Based on MOS 2364 ROM.
- Datasheet (Feb 1980)
- In addition to programming the 8KiB of data, you also have to program the chip select pin state ("enable high" or "enable low"). For the BASIC ROM, this is "enable low".
- 8KiB ROM, provides the machine code for the kernal routines.
- Printed name: "MOS 901227-02" or similar.
- Based on MOS 2364 ROM.
- Datasheet (Feb 1980)
- In addition to programming the 8KiB of data, you also have to program the chip select pin state ("enable high" or "enable low"). For the Kernal ROM, this is "enable low".
- 4KiB ROM, provides the font data.
- Printed name: "MOS 901225-01" or similar.
- Based on MOS 2332 ROM.
- Datasheet (Feb 1980)
- In addition to programming the 4KiB of data, you also have to program the chip select pin state ("enable high" or "enable low") for both CS1 and CS2. For the Character ROM, CS1 is "enable low" and CS2 is "enable high".
- Datasheet
- Datasheet (Nov 1982)
- More info Wikipedia myoldcomputer
- 7406/7416
- Texas Instruments SN7406N Datasheet
- This is the same as the 74LS257 but with inverted outputs.
- Hitachi HD74LS258 Datasheet
- OKI MSM4966RS
- Hitachi HD14066B Datasheet
- Printed name: "MOS 906114-01" or similar
- Older models named 82S100 (?)
- The C64 PLA Dissected by Thomas 'skoe' Giesel (other versions)
- Links to PLA-related code: zimmers.net
- More info: C64Wiki
- Printed name: "MOS 6567 R8"
- Specification sheet (preliminary
- The MOS 6567/6569 video controller (VIC-II) and its application in the Commodore 64 by Christian Bauer
- More info: Wikipedia C64Wiki
- Texas Instruments SN74LS629 Datasheet
- Motorola MC4044P Datasheet