I've experienced the same as Goldstar. Some systems can detect less simultaneous keypresses than others.
Incidentally, there’s a post by Mark in
this topic, that I found useful regarding input handling. Specifically:
marksibly:
Currently, Max assumes your app is running in either 'polled' or in 'event driven' mode - although users have mixed the 2 with varying degrees of success...
The idea here was that in polled apps, users wouldn't have to worry about PollSystem - it would be automatically handled whenever user input is queried (KeyDown, AppTerminate etc).
Event drivens apps on the other hand would get full control of when PollSystem occured, via PollSystem, WaitSystem, PollEvent or WaitEvent - and I like this degree of certainty.
Once I changed my framework to be fully dependent on ‘event driven mode’ (as opposed to mixing ‘polled’ and ‘event driven’), all the glitches I was experiencing vanished. (Though you’ll still be limited by a maximum number of simultaneous keypresses on a per system basis).