Opcom 1.67 Firmware Review

The majority of interfaces running firmware 1.67 utilize a hardware design centered around the FTDI FT232RL USB-to-Serial converter and a microcontroller (often an AVR or PIC architecture, depending on the clone quality). The firmware resides within the microcontroller’s flash memory.

If you have a purchased after 2018, attempting to force firmware 1.67 might actually brick your interface. Most clones today require 1.95 or higher due to different PIC microcontrollers. Opcom 1.67 Firmware