Head-Wedge from POTF
Torso, Upper Arms-Duke
Lower Arms-Flint
Upper right leg-Hawk
Upper left leg-Beachhead
Lower Legs-Gung Ho
Lower Feet-not sure
Gloves, bandolier-Mainframe
Helmet-modded not sure which figure
Knife-BBI figure (added a strap to resemble the original figure and cartoon look)

I really liked Mainframe. I always thought his file card was pretty cool in that he was a vet who had thrown away fighting and was now a computer geek.
The 80's comic had him pretty active in a couple of issues but for me, once again, it was the cartoon where the character really stood out. The voice actor nailed the part and Mainframe became, in my opinion, one of the coolest Joes of that season and in the run of the GiJoe mythos.
I was never crazy about his computer-borgified look of the Devils Due run but I give them credit for trying to make things unique about the characters.