Yes, the Ninja Tap = 4 x joystick + 4 x 2 buttons on one port. So with the same method we can make at least one joystick with 20 buttons. And that's without counting the Run and Select buttons that we can add as for the FM-Towns controllers.
If you include 'up' and 'down' as button, 'left' and 'right' as button, you have indeed. Furthermore, ' up, left' and 'down,right' , or 'up ,right' and 'down,left' also a similar combo.
Theoretically 22 (16+6), excluding combination of other buttons because of their purpose.
Do not forget an MSX has, as far as I know, always 2 ports,
Having 2 controllers and let's say, excluding movement, (almost) 20 , buttons, totall with 2 controllers,40 buttons to press, would be an overkill for me...., But who am I ?
A 17 button controller, 2x movement, run, pause, 4 action button and fast firing button (only on controller side, no connection with MSX port), is fine for me,
For detection of the controller, make the first row inverse, so always power on pin 1-4, no power on line, is pressed.
I was just thinking about the button issue and thought of some kind of modular controller.
Exchangeable and Interchangeable parts of controller.(per 4 buttons)
If there is no need for 2 cyclones (movement controllers), slide out second, and slide in a blank top or slide in 4 extra action buttons...
If people do not use 4 rows, but only 3, vibration/feedback can be installed , etc
Modular Joypad, meeting your needs and beyond! Maybe you can even get a patent.
If the controller is working perfectly at some point, provide patches (where possible) in order to use controller over other '1980s controllers'
As promised, this is in basic and using KUN-BASIC ( CALL TURBO ON / OFF).
Using OpenMSX, the version I tested with, does not show colors correctly.
It's basic, so you can see for yourself.. Cursor and mouse game
