On FoxWiki, there is an entry about SYS(2050) which apparently creates some sort of log file. The function does not appear in the VFP Help file - anyone know anything more about it?
It's the VFP event loop log. Basically, it records mouse clicks and key strokes. The first column is the current time, second column the event (key up, down, click), third column a qualifier (key for keyboard events, Ctrl/Shift/Alt state for mouse click). The fourth column is probably the encoded 32-bit message that VFP uses internally (ie. the same as column 2 and 3).