Ch351q Parallel Port Driver May 2026

Taming the CH351Q: A Guide to Getting Your PCIe Parallel Port Working on Modern Windows

If you’re reading this, you probably have a niche need: an old printer, a CNC controller, an EPROM programmer, or a piece of industrial machinery that only speaks via the parallel port. Your modern PC doesn’t have one, so you bought a PCIe card based on the CH351Q chip.

: Windows 11/10/8.1/8/7/Vista/XP (32/64-bit) and Linux (usually via the parport_pc or specific WCH kernel modules). 2. Installation Guide (Windows) : Obtain the CH35XDRV.EXE CH35XDRV.ZIP package from the official WCH download page Run Installer ch351q parallel port driver

Hobbyists have written custom wrappers around the default WCH drivers to: Taming the CH351Q: A Guide to Getting Your

Key functionality

• Enumerates CH351Q via USB and binds to it.
• Claims the device as a parallel port class (or uses a vendor-specific protocol if not standard).
• Implements read/write control transfers and bulk/interrupt endpoints as required to emulate parallel data, status, and control lines.
• Supports modes: SPP (basic), EPP/ECP emulation where possible, and GPIO toggling for non-parallel use.
• Exposes device node(s) compatible with common parallel-port utilities and libraries (libieee1284, ppdev on Linux).

While the chip was designed for printers, the hacker community uses it for everything but printers. Because the CH351Q provides direct access to 8 data lines and 4 control lines (standard SPP mode), it is effectively a cheap 12-pin GPIO controller. Enumerates CH351Q via USB and binds to it

• CH351Q chip: WCH Corporation
• Driver version: 1.0
• Operating system: Windows XP, Windows Vista, Windows 7, Windows 8, and Windows 10
• Interface: Parallel port (ECP and EPP modes)
• Data transfer rate: Up to 2.5 Mbps

Installation: Run SETUP.EXE within the extracted folder. Windows should automatically detect the "PCI Parallel Port" or "PCI Serial Port" after a reboot. ⚠️ Common Troubleshooting Tips

Part 6: Troubleshooting Common Driver Issues

Error Code 10 (Device Cannot Start)

• Cause: Resource conflict or missing firmware.
• Solution: Go to BIOS → Disable onboard LPT if present. In Device Manager → Change the port’s I/O range via the "Advanced" tab (if available in CH35X properties).

Verify in Device Manager. You should now see: