Opcom firmware 1.70/1.65 updated! But how to downgrade Opcom firmware to version 1.39? Here you go.
Free download all picture, .ept and pic18f458 v1.39 files in rar:
How to downgrade OPCOM firmware to 1.39
Circuit serial programming connection
Press Open and slect v1.39 pic 18f458 files
Then do as the pictures display
Done! Successfully downgrade OPCOM fw 1.39 without Bootloader error!
NOTE: YOU WILL TRY ON YOUR OWN RISK.
CREDITS to AKI1 in the MH community