A
750 version
s_left 	s_right t_bottom t_top
0   	6  	0	196		// comment: altitude 10000
6   	12  0	196		// comment: altitude 1000
12   	18	0	196		// comment: altitude 100
18 		30 	9	66		// comment: altitude 10  (20 feet of increment)
100						// comment: feet per tickmark (small)
500						// comment: feet per tickmark (big)
200						// comment: feet per label
0.15					// comment: pixels per foot
