A
870 version
s_left 	s_right t_bottom t_top
 0	 7	0	196	// comment: altitude 100000
 7	14	0	196	// comment: altitude 10000
14	21	0	196	// comment: altitude 1000
21	27	0	196	// comment: altitude 100
27	38	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
