The driver is hosted on WCH’s official website (wch.cn). Navigate to:
As of my last update, the stable version is CH35X DRIVER V1.7 (or later for Windows 11). The package includes:
The CH351Q is supported by the Parport subsystem with the parport_pc module, but you may need to manually bind it.
For persistent configuration, add options parport_pc io=0x378 irq=none to /etc/modprobe.d/parport.conf. ch351q parallel port driver
Note: Some CH351Q cards do not trigger automatic IRQ assignment. Use irq=none for polling mode.
Writing a driver for the CH351Q isn't just about turning pins on and off; it is about tricking the OS.
Modern versions of Windows (10/11) and Linux have mostly abstracted printer ports away. They treat printers as high-level devices managed by the spooler, not as raw hardware addresses a user program can poke. However, legacy software—like a DOS-based CNC controller or a hobbyist JTAG programmer—expects to write directly to a memory address (e.g., OUT 0x378, AL). The driver is hosted on WCH’s official website (wch
The Challenge:
The CH351Q, sitting on the PCI bus, does not natively live at 0x378. The PCI bus assigns it a dynamic memory address (BAR, or Base Address Register) during boot.
The Solution: The CH351Q driver performs a clever trick called Port Mapping.
If you cannot get the CH351Q driver to function, consider these alternatives: As of my last update, the stable version is CH35X DRIVER V1
| Solution | Pros | Cons | |---------|------|------| | Native motherboard LPT header | Zero driver issues | Obsolete on new boards | | USB-to-parallel (e.g., IEEE-1284 compliant) | Easy plug-and-play | Fails with dongles & low-level I/O | | CH353L-based PCIe card | Similar driver package | Different INF may be needed | | Raspberry Pi with GPIO to parallel | Extremely flexible | Requires custom software |
However, for true hardware-level LPT emulation, the CH351Q remains the best balance of cost and compatibility—provided you have the correct driver installed.
| Symptom | Likely Fix | |--------|-------------| | Device Manager shows a yellow bang | Boot with signature enforcement off, reinstall driver | | Port shows but no data output | Check if your software needs EPP/ECP mode – CH351Q supports only SPP (Standard) mode | | Mach3 says "Driver not loaded" | Use the Mach3 parallel port driver with the address override | | Blue screen on resume from sleep | Known issue – disable power management for the PCIe slot |