100 REM Map range
110 DECLARE EXTERNAL FUNCTION MapRange
120 FOR I = 0 TO 10
130    PRINT USING "## maps to ##.#": I, MapRange(I, 0, 10, -1, 0)
140 NEXT I
150 END
160 REM *****************************************
170 EXTERNAL FUNCTION MapRange(S, A1, A2, B1, B2)
180 LET MapRange = B1 + (S - A1) * (B2 - B1) / (A2 - A1)
190 END FUNCTION