This a controller for 8/16 bit home computers. This controller gives you 6 buttons total. Left ones are standart up, down, left and right buttons. But you can customize right pair of buttons as your wish and computer. I inspired from shape of NES controller. It is compatible with basically all computers, commodore, atari, amstrad, spectrum, amiga...

There are few ways of doing that:

1) both buttons are fire buttons
2) top one is up, bottom one is fire
3) both of them are seperate fire buttons

Option 1 is good if you're playing games doesn't need you to constantly hold fire button, option 2 is good for games that you need to constantly hold up button to move, option 3 is good for computers with 2 seperate fire buttons like amstrad and amiga.