Decode Floating Point Value 2

This program works with BASICS I-IV and decodes or encodes a Floating-Point variable (or the Floating Point Work Area - FWA) between a Numeric Decimal value and the Internal BASIC representation.
You can choose to (1) enter the Exponent and Mantissa values in Hexadecimal format and the program will return the numeric decimal value or (2) enter the numeric decimal value and have the program return the Internal BASIC representation of that value.

   10 REM FLOATING POINT VARIABLE-DECIMAL
   20 Z=0
   30 PRINT''
   40 INPUT"1) VARIABLE TO DECIMAL"'"2) DECIMAL TO VARIABLE"'"3) FWA TO DECIMAL"';A$
   45 IF A$="3" GOTO 200
   50 IF A$="2" INPUT''"Enter value ";Z
   60 IF A$="2" I%=3+?&4B4+256*?&4B5: PRINT'"Varable is:"'"Exponent  : ";~?I%'"Mantissa1 : ";~?(I%+1)'"Mantissa2 : ";~?(I%+2)'"Mantissa3 : ";~?(I%+3)'"Mantissa4 : ";~?(I%+4)'
   65 ONERROROFF
   70 IF A$="1" INPUT''"Enter Exponent &"B$:B%=EVAL("&"+B$)
   75 ONERRORGOTO70
   80 IF A$="1" INPUT"Enter Mantissa1 &"B$:C%=EVAL("&"+B$)
   85 ONERRORGOTO80
   90 IF A$="1" INPUT"Enter Mantissa2 &"B$:D%=EVAL("&"+B$)
   95 ONERRORGOTO90
  100 IF A$="1" INPUT"Enter Mantissa3 &"B$:E%=EVAL("&"+B$)
  105 ONERRORGOTO100
  110 IF A$="1" INPUT"Enter Mantissa4 &"B$:F%=EVAL("&"+B$)
  120 IF A$="1" I%=3+?&4B4+256*?&4B5:?I%=B%:?(I%+1)=C%:?(I%+2)=D%:?(I%+3)=E%:?(I%+4)=F%:PRINT'"The decimal is : ";Z
  130 RUN
  140 INPUTA
  150 ?&402 = 2: PRINT"Fixed=";A
  160 ?&402 = 1: PRINT"Scientific=";A
  170 ?&402 = 0: PRINT"General=";A
  180 END
  200 REM FWA TO DECIMAL
  210 INPUT''"Enter Exponent &"B$:B%=EVAL("&"+B$)
  215 ONERRORGOTO210
  220 INPUT"Enter Mantissa1 &"B$:C%=EVAL("&"+B$)
  225 ONERRORGOTO220
  230 INPUT"Enter Mantissa2 &"B$:D%=EVAL("&"+B$)
  235 ONERRORGOTO230
  240 INPUT"Enter Mantissa3 &"B$:E%=EVAL("&"+B$)
  245 ONERRORGOTO240
  250 INPUT"Enter Mantissa4 &"B$:F%=EVAL("&"+B$)
  260 I%=3+?&4B4+256*?&4B5:?I%=B%:?(I%+1)=C%:?(I%+2)=D%:?(I%+3)=E%:?(I%+4)=F%
  270 X=ABS(Z)
  280 IF C%>0 ANDC%<&80 THEN I%=3+?&4B4+256*?&4B5:?I%=B%:?(I%+1)=&80:?(I%+2)=0:?(I%+3)=0:?(I%+4)=0:X=Z+X
  290 PRINT'"The decimal is : ";X
  400 RUN