'this little proggy shows the speed of my new command for clearing the screen! 
'!!! at this moment you can't give a colour parameter as with the normal Cls 
'    instruction...I'll change this in the future...                       !!! 
'
'!!! you get the speed in Vertical Blancs...the lesser the faster... 
'
Screen Open 0,320,200,4,Lowres
Multi No 
T=Timer
For I=1 To 100
   Cls 0
Next 
Print "Time in VBL's";Timer-T
Print "Left mouse button..."
Repeat 
Until Left Click
T=Timer
For I=1 To 100
   Blit Clear -1
Next 
Print "Time in VBL's";Timer-T
Print "Left mouse button"
Multi Yes 
Repeat 
Until Left Click