Max number of rows and colums

[picontrolit]

I have an old commodore keyboard with 8 rows and 16 cols. I adjusted the example sketch but keypresses are not detected at all.
I wonder if there is a maximum amount of cols and rows supported by the keypad library.
Especially this line from keypad.h seems to define a hard limitation.

#define MAPSIZE 10 // MAPSIZE is the number of rows (times 16 columns)