Ultimately, the 7800 support is more important to me. I was proceeding under the mistaken impression that the mode switches were checked during powerup, and then became available for reuse in 2600 mode.
I have removed my second db9 and cleaned up the board. 7800 mode remained unusable. You gave me a good hint though; upon reprogramming with the "2600-daptorII TB FB1.hex", 7800 sticks now work again. I must have corrupted the firmware somehow with my 2600 twin stick.
Your download links for the MPHidflash for Linux are dead. I looked it up on Github and failed at building it, as for whatever reason apt-get couldn't find libhid-dev to install it, so I had to reprogram the 2600-daptor II from Windows.
Here is a firmware for the 'II with it forced in 7800 mode (a "7800-daptor" if you will) -
http://2600-daptor.c...I 7800 only.hex
Extra buttons inputs 5 & 6 are now free to be used. Set the mode select switches up (else they will force these inputs on). #4 is still used for firmware updates, but this only checked when the 'daptor is first powered on, after that is free to be used. However, I have occasionally seen that the USB can be reset when a controller is plugged in, and if input 4 was on, the 'daptor would get kicked into firmware update mode. Unplug the USB and reconnect with #4 off should get back to normal operation mode.
Thanks for pointing out the dead link. Yeah, looks like the project moved over to GitHub -
There is "binaries" folder with executables for various O/S's including Linux.
Edited by dualcam, Thu Mar 9, 2017 10:11 AM.