User flash_master uploaded a zip containing the tool + USB drivers for Windows 10/11. techforum.com/attachments/sunplus_loader_tool_with_drivers.zip (Requires free signup)
Lemmy Morgan : Offers downloads for and v1.5.0.8 . sunplus loader tool link
Click "Start" or "Upgrade" in the loader software. User flash_master uploaded a zip containing the tool
Before you start, you will need a or a USB-to-RS232 Adapter if your PC lacks a serial port. Step-by-Step Instructions: sunplus loader tool link
The Sunplus Loader Tool is a "low-level" tool. It writes directly to the memory of the device. If you interrupt the process or use a firmware file intended for a different board revision, you could render your device unrecoverable. Always verify that the firmware matches your Mainboard Version number before flashing.