The ByteCradle 6502 is a single-board computer (SBC) platform designed for understanding and experimenting with simple operating systems on 8-bit hardware. Built around the WDC 65C02 microprocessor, it provides a hands-on platform for studying system initialization, memory management, device interfacing, and file system handling.
- BYTECRADLE 6502
- Overview
- Tier Comparison
- Obtaining PCBs
- Download ROMs
- License
- Contributing
- Acknowledgements
Both SBCs share a common design philosophy — to provide a straightforward and accessible 65C02 system, while exploring different levels of hardware capability.
- CPU: WDC 65C02
- I/O: WDC 65C51 Asynchronous Communications Interface Adapter (ACIA)
This project offers two tiers of single board computers (SBCs), each tailored to different levels of complexity and expandability:
- Tiny SBC (top): A simple, compact design ideal for learning or small embedded projects.
- Mini SBC (bottom): A more capable version with bank switching, SD card storage, and an expansion bus using the 65C22 Versatile Interface Adapter (VIA).
| Feature | Tiny SBC | Mini SBC |
|---|---|---|
| PCB | Two layer | Four layer |
| RAM | 32 KiB | 512 KiB (bank switched) |
| ROM | 32 KiB | 512 KiB (bank switched) |
| Bank Switching | ❌ | ✅ (64 x 8 Kib banks) |
| SD Card Support | ❌ | ✅ (via WDC 65C22 VIA) |
| I/O Interface | WDC 65C51 ACIA | WDC 65C51 ACIA |
| Expansion Options | Exposes system bus | Exposes system bus and VIA bus |
You can have the ByteCradle PCBs manufactured at any PCB fabrication service of your choice. However, for convenience and ease of ordering, we recommend using PCBWay.
The following links will take you directly to the shared projects on PCBWay, where you can order the boards:
Note
These links direct you to the official project pages for the Mini and Tiny Boards on PCBWay.
Below are the available ROM images for use with the ByteCradle single-board computers. These ROMs can be flashed onto your device depending on the board you are using.
-
TinyROM
A lightweight ROM designed specifically for the Tiny Board. Ideal for minimal setups, testing, or basic 6502 development. -
ByteCradle Operating System ROM
A more feature-rich ROM intended for the Mini Board. This includes support for SD card storage and is better suited for more complex applications and multitasking environments.
Important
Make sure to select the appropriate ROM for your board model. Flashing the incorrect ROM may result in system instability.
All software (including ROM code, tools, and firmware) in this repository is licensed under the GNU General Public License v3.0.
This means:
- You are free to use, modify, and share the software.
- If you distribute modified versions, you must also release them under the GPLv3.
All hardware design files (schematics, PCB layouts, bills of materials, etc.) are licensed under the CERN Open Hardware License v2 - Weakly Reciprocal (CERN-OHL-W).
This means:
- You may study, modify, manufacture, and distribute the hardware freely.
- If you distribute a modified version, you must share your changes under the same license.
Contributions, ideas, and improvements are always welcome. Open an issue or submit a pull request to get involved!
We gratefully acknowledge PCBWay for their generous support in sponsoring the prototype PCB manufacturing of the Mini Board. Their assistance helped accelerate the development and testing of the hardware, and we appreciate their commitment to supporting open hardware projects.