difficulty select for Loopz, by hap, feb 17th 2006

Andreas Daumann's Loopz was originally only for HP48
this change adds difficulty select within the SCHIP program, so it'll work
on SCHIP emulators, no changes were made in the main program

to select difficulty:
same keys as in loopz: c=up, d=down, 5=ok

v0,v1,v2 are set before running loopz
v1 and v2 should be $AA, dunno why
v0 is the difficulty (0 to 9)
saved into flags and the game runs as normal

original loopz program: $200-$f9d
difficulty select: $f9e-$fff (full ;p )

