Display
The display from my Net Yaroze is completely grey and
grainy / shudders
You may be running an NTSC configured program on a PAL
configured monitor.
If you have the source, make sure that the program contains
a SetVideoMode(MODE_PAL) command and does not contain
a SetVideoMode(MODE_NTSC) command.
If you only have the executable, you can pick up the
'Screen Mode Changer' (N!K/Napalm) from the Napalm hacker site
(see link section) - it is able to change executables which contain
a SetVideoMode(...) command.
If, like me, you own an old Amiga monitor (1084/1084S/CM1884), an
RGB to SCART cable should do the trick - forget your old Amiga lead!
I am trying to use graphic functions, but the screen
locks / judders
These kind of effects can occur when you haven't allocated
enough GPU packet space.