C64 Open source cartridges and programmers

C64MegaCart V4.3

• 2 Megabyte of Flash memory
• Flash can be erased, either the whole memroy or smaller banks, and written by the C64
• When ordering 100 units, each unit should cost about USD 10, excluding shipping and import taxes.
• Can be ordered direct from PCBWay: https://www.pcbway.com/project/shareproject/Commodore_64_MegaCart_V4_3_2MB_eafeb0e4.html
• Code that demonstrates erase and write of a cartridge with some example boot code: https://github.com/martinpiper/C64MegaCart/blob/main/WriteCartTest.a
• Code that demonstrates flash memory erase and write, with cartridge bank kill functionality: https://github.com/martinpiper/C64MegaCart/blob/main/FlashWriteTest.a
• Assembled prg files for this example code are also in this repository.
• Source code for the stdlib includes can be found in this repository: https://github.com/martinpiper/C64Public/tree/master/stdlib

Cartridge programmer tool

• This is a Raspberry Pi hat
• Software running on the Raspberry Pi can erase, write, and read the flash memory
• Setup video: https://www.youtube.com/watch?v=GBg5k46B5Pw
• Setup instructions: https://github.com/martinpiper/C64MegaCart/blob/main/PiCartTool/ReadMe.md#setup-software-using-gcc
• It multiplexes signals to increase the number of inputs and outputs, allowing the full range of Commodore 64 expansion port signals to be controlled
• It uses MOSFETs to drive higher currents at higher frequencies
• Can be ordered direct from PCBWay: https://www.pcbway.com/project/shareproject/C64_Cartridge_programming_tool_V2_4b4c9cff.html
• Raspberry Pi source code for the programmer is here: https://github.com/martinpiper/C64MegaCart/tree/main/PiCartTool

About PCB assembly costs

PCBWay have fixed assembly and fabrication setup fees, so when ordering a small number of units these fees increase per unit cost. The best way to reduce the impact of setup fees is to order more units, in bulk.

Cartridge case for normal sized PCBs

• Case assembly video: https://www.youtube.com/watch?v=x988wTCP7Js
• C64MegaCartNormalCase.FCStd
• Can be used with: FreeCAD_1.0.2-conda-Windows-x86_64-py311
• Top part: https://www.pcbway.com/project/shareproject/Commodore_64_MegaCart_case_Top_f965217a.html
• Bottom part: https://www.pcbway.com/project/shareproject/Commodore_64_MegaCart_case_Bottom_1492af35.html

Vice 3.1 support

• Vice 3.1 Win32 DirectX build with C64MegaCart support: https://github.com/martinpiper/Vice-3.1-with-C64MegaCart/tree/main/vice-3.1/data
• There are many hooks for the cartridge system, the main source is in: https://github.com/martinpiper/Vice-3.1-with-C64MegaCart/blob/main/vice-3.1/src/c64/cart/c64megacart.c