Anyone? Here's the code for those of you who don't want to dig it out...
Code:
SETV a1,5
COUNT SETV d1,70; projectile countdown: fire at 0
LOOP SUBV d1,1
WAITFRAME
COMPAREV x,180; reached right edge?
GOTOLESS MORE
SETV xd,-1; reverse speed
MORE COMPAREV x,40; reached left edge?
GOTOMORE PROJ
SETV xd,1; reverse speed
PROJ COMPAREV data,0
GOTOTRUE 19
COMPAREV d1,0; now we handle the projectile
GOTOMORE LOOP
SETA1 x,x
SETA1 y,y; place the projectile
SETV d0,21
SETA1 data,d0; set its sprite
GOTO COUNT
QUIT