It does work on older devices, but, kinda annoyingly slow. Made a few tweaks to see if I could improve the speed, but not much improvement on older devices, some significant improvement on Roku2, however:
BtnPrs = Msg.getmessage()
eliminates the wait delay
m.WorldMaxX = (20 * 1024) - 1 'Maximum coord still on the map m.WorldMaxX10=m.worldmaxX/1024 m.WorldMaxY = (20 * 1024) - 1 'Maximum coord still on the map m.WorldMaxY10=m.worldmaxY/1024
create constants for things that always calculate out to the same value, including replacing 3.14159/180 with 0.0174533 on the Scrn.Drawline at the end of the drawworld function
moved "SetAlphaEnabled(false)" to the line following the creation of the roScreen and removed alpha from the loop, don't see any problems without it.