[MiNT] VBL tasks

[Oddie Jonathan <oddie@bvsd.k12.co.us>]

hi again,

At the moment I am trying to write an XDD to emulate a sun-style /dev/mouse
under MacMiNT (w1r4 needs one & jet doesn't emulate it). But I have a couple
of questions:

1. What's the format of the m_buttons thing? From what I've seen of the
 mint sources, I think it's this: 0x8 in the high byte; in the low byte,
 least significant bit is left button, then middle, then right, with 0 being
 down... is this right?

2. How do I install a task in the VBL queue (without destroying any others
 that may be in there)? And what are the limitations on what a VBL handler
 can do (what registers does it have to preserve, etc)

Thanks



Jonathan