[RE] x65
X65 is a modern retro computer using 65C02/65816 CPUs, VERA FPGA for video/audio, and Wiznet W6100 for full IPv4/IPv6 Ethernet networking support.
🔎 Overview
The X65 Project is a modern take on the classic retro computer, built around the WDC 65C02 or 65C816 microprocessor. It blends the charm of 8/16-bit computing with modern features like Ethernet networking, FPGA-based video/audio, and Python-based debugging tools—making it an ideal platform for firmware developers, RTL designers, retro computing enthusiasts, and embedded systems engineers.
⚙️ Hardware Specifications
| Component | Description |
|---|---|
| CPU | W65C02S (8-bit) or W65C816S (16-bit) |
| Memory | 2MB SRAM with memory banking via RAMBLOCK/ROMBLOCK registers |
| Video Output | VERA FPGA (open-source, VGA-compatible, 128KB VRAM) |
| Audio Output | PCM, PSG, and FM synthesis (YM2151 via Verilog – AURA module) |
| Networking | Wiznet W6100 – Hardware TCP/IP Stack with IPv4/IPv6 support |
| I/O Ports | PS/2 keyboard & mouse, SD card, USB device, Ethernet, UEXT connector |
| Board Format | 4-layer PCB single-board computer (SBC) |
🌐 Ethernet on X65 – Powered by Wiznet W6100
The X65 integrates a Wiznet W6100 Ethernet controller, which brings full-stack hardware networking capabilities into the 8/16-bit computing realm.W6100 Highlights:
10/100 Mbps Ethernet
Supports both IPv4 and IPv6
Hardware TCP/IP Stack (TCP, UDP, ICMP, IGMP)
Simplified microprocessor interface
Integrated into X65 through memory-mapped I/O and Verilog-defined interface logic via the NORA FPGA
Use Cases on X65:
Remote debugging via Ethernet
Lightweight web server or client using W6100 stack
TFTP booting and network-based development
IoT-style communication from a 65C816 system
🧠 Memory & System Architecture
The 65C02 uses a 64KB address space, while the 65C816 supports a 24-bit address bus (16MB max).
The X65 system implements bank switching via RAMBLOCK and ROMBLOCK control registers.
The VERA video/audio module and W6100 are mapped into the I/O space for efficient access.
For detailed memory map documentation, see:
👉 Memory Map Doc
🎮 Video & Audio Subsystem
VERA FPGA: Provides high-resolution VGA video and PSG-style sound.
AURA (YM2151 FPGA): A cycle-accurate FM synthesis implementation using Verilog, enabling arcade-quality audio from a classic CPU.
🔧 Debugging and Development Tools
Python-based host CLI tools: Interact with X65 memory, I/O, and firmware uploads directly from your PC.
USB-C debug interface: Supports in-circuit debugging and quick firmware flashing.
🧪 Why X65 Matters
X65 isn’t just a retro machine—it’s a fully capable hardware-software co-design platform for engineers and makers. Whether you’re:
Exploring WDC-based assembly programming
Writing bare-metal firmware with memory-mapped peripherals
Testing custom Verilog modules in a live system
Implementing embedded networking via Wiznet’s W6100
…the X65 can be your hands-on lab.
📂 Related Repositories
🔩 x65-mech: Mechanical design files (case, mounting, layout)
🎮 VERA module: Video & audio FPGA engine
🎵 AURA (YM2151 Verilog): FM synthesizer in HDL
📈 SEO Tags (for metadata)
✅ Final Thoughts
The X65 project is a one-of-a-kind blend of retro CPU charm and modern embedded systems engineering. It's open-source, highly hackable, and perfect for WIZnet-powered networking experiments. With the W6100, engineers can bring vintage processors into the modern web-enabled world.
👉 Check out the full project: GitHub - jsyk/x65
Keywords: 65C02, 65C816, retro computer, W6100 Ethernet, FPGA SBC, Python debugger, VERA, YM2151, WDC CPU, X65 board, Verilog