Despite being legacy software, version 6.85 is incredibly robust and feature-rich:

If the software displays a "Device Not Found" or "Programmer Disconnected" error:

What version are you running? (Windows 10, 11, Linux?)

Parallel ROM/EPROM/EEPROM (26, 27, 28, 29, 37, 39, 49, 50 series); Serial EEPROM (24, 25, 35, 85, 93, 95 series); Microcontrollers (AVR, ATMEGA, PIC10/12/16/18); GAL logic devices.

and may cause compatibility issues.

For users who want true "latest version" functionality—including support for new chips, bug fixes, and modern operating systems—the unofficial open-source project (also known as minipro-tools ) is the definitive answer. Developed by Kristian Lauszus and other contributors, this project reverse-engineered the TL866CS communication protocol.

Supports TL866CS, TL866A, and TL866II Plus. No firmware update risk.