How to make keyboards read multiple button presses?

Does anyone know if its possible to make a keyboard read multiple button inputs in one frame?

this normally isnt an issue (actually a gift because it allows easy plinking) until i start playing gouki. the demon flip grab is impossible to do on a keyboard without setting one of your buttons as throw.

Quick Question are you using a p/s2 (older connector, uses din 6 I believe) keyboard or usb?

USB keyboards are limited to a max of 6 keys plus 4 Modifiers. Modifiers are Shift, Crtl, Alt, Super key (aka the windows key) and ether AltGr or FN.

If you want n key rollover"aka unlimited button pushes" you will want a non-usb or ps/2 keyboard.
Also take note not all p/s2 keyboards have this feature.

As per your question, No the limitation to the number of max key presses in a keyboard is in the hardware keyboard encoder inside your keyboard. Personally I notice good keyboards are just as expensive as an arcade fight stick.