Need Acceleration Code for 3D Asteroid'sh Game

Something like the following should do nicely :D ( use the right arrow key to speed up!

Graphics 640,480
SetBuffer BackBuffer()



Global speed# = 0
Global acc# = 0.5

Global speed_scale = 3
Global cut_off = 80 ; no more than 90, as it's a wave, it will decrease after 90

Global x# = 100
Global y# = 200

While Not KeyHit(1)

	Cls

	If KeyDown(205) Then
		speed = speed + acc
		If speed > cut_off Then
			speed = cut_off
		End If
	Else
		speed = speed - acc
		If speed < 0 Then speed = 0
	End If
	
	x = x + Sin(speed) * speed_scale
	If x > 640 Then x = 0
	
	Oval x,y,20,20
	
	Flip
	
Wend
End