The gravis gamepad "cheats" a little and actually presses buttons A/B on joystick 1 and A/B on joystick 2
Instead of 4 axises, 4 buttons, and a complicated timer based system to calculate axis positions, it only uses 2 "buttons"
It'd read their input and wrap it into a GrIP packet, so you could use it with GrIP supporting games or Windows 95.
The software was great, you could optionally map the buttons to keyboard keys and such.
It's like a SNES controller, but with two extra buttons: L2 and R2.
So I mapped them to the "save state" key and "load state" key in my emulator, and cheated like crazy.