9000  REM   ***** SUBROUTINE ALFTOV *****
9001  REM
9002  REM     CONVERTS AN ALPHA NUMBER TO A VARIABLE
9003  REM
9004  REM  INPUT:  A$, INPUT STRING
9005  REM          Z0, INDEX TO BEGIN SCAN
9006  REM  0UTPUT: Z,  RETURNED VALUE
9007  REM          Z0, INDEX AFTER LAST VALID CHARACTER
9008  REM
9009  DIM Z$[15]
9010  REM
9011  LET Z=Z4=Z5=0
9012  LET Z1=Z2=Z3=1
9013  LET Z$="0123456789+-.E "
9015  FOR Z9=Z0 TO LEN(A$)
9016  FOR Z8=1 TO 15
9017  IF A$[Z9,Z9]=Z$[Z8,Z8] THEN 9020
9018  NEXT Z8
9019  GOTO 9080
9020  IF Z8=15 THEN 9070
9021  IF Z8>10 THEN 9040
9022  GOTO Z2 OF 9025,9030,9035
9025  LET Z=10*Z+Z8-1
9028  GOTO 9070
9030  LET Z5=Z5+1
9031  GOTO 9025
9035  LET Z4=10*Z4+Z8-1
9037  GOTO 9070
9039  REM
9040  GOTO Z8-10 OF 9045,9045,9055,9060
9045  IF Z2<3 AND Z>0 THEN 9080
9046  IF Z2=3 THEN 9050
9047  LET Z1=23-2*Z8
9048  GOTO 9070
9050  IF Z4>0 THEN 9080
9051  LET Z3=23-2*Z8
9052  GOTO 9070
9055  IF Z2>1 THEN 9080
9056  LET Z2=2
9057  GOTO 9070
9060  IF Z2=3 THEN 9080
9061  LET Z2=3
9070  NEXT Z9
9075  REM
9080  LET Z0=Z9
9081  IF ABS(Z3*Z4-Z5)<50 THEN 9085
9082  LET Z5=Z3*(Z4-50)
9085  LET Z=Z1*Z*10^(Z3*Z4-Z5)
9087  RETURN 
9090  REM   ***** END ALFTOV *****
