'===========================================================================
' Subject: UPDATE OF BASE CONVERSION         Date: 11-14-96 (16:16)       
' Author:  Tyler Barnes                      Code: QB, QBasic, PDS        
' Origin:  comp.lang.basic.misc            Packet: ALGOR.ABC
'===========================================================================
'Here's an update to my base conversion thing. This version is smaller,
'faster, and neater. (I simplified a part at the end and removed some of
'the exponent stuff I was doing.)

DECLARE SUB Base2Base (Number1$, Digits1$, Number2$, Digits2$)
CONST Bin = "01", Oct = "01234567", Dec = "0123456789", Hex = "0123456789ABCDEF

SUB Base2Base (Number1$, Digits1$, Number2$, Digits2$)
Number1$ = UCASE$(Number1$): Digits1$ = UCASE$(Digits1$)
Digits2$ = UCASE$(Digits2$): Number2$ = ""
IF Digits1$ <> "0123456789" THEN
FOR I% = LEN(Number1$) TO 1 STEP -1
IF Digits1$ = "01234567" THEN FinalNum& = VAL("&O" + Number1$): EXIT FOR
IF Digits1$="0123456789ABCDEF" THEN FinalNum&=VAL("&H"+Number1$):EXIT FOR
CD$ = MID$(Number1$, I%, 1)
CV% = INSTR(Digits1$, CD$) - 1
FinalNum& = FinalNum& + (CV% * (LEN(Digits1$) ^ ABS(I% - LEN(Number1$))))
NEXT I%
ELSE
FinalNum& = VAL(Number1$)
END IF
IF FinalNum& < 0 THEN FinalNum& = FinalNum& + 65536
IF Digits2$ = "0123456789" THEN Number2$ = LTRIM$(STR$(FinalNum&)): EXIT SUB
IF Digits2$ = "0123456789ABCDEF" THEN Number2$ = HEX$(FinalNum&): EXIT SUB
IF Digits2$ = "01234567" THEN Number2$ = OCT$(FinalNum&): EXIT SUB
DestBase% = LEN(Digits2$)
DO
Remainder% = FinalNum& MOD DestBase%
FinalNum& = (FinalNum& - Remainder%) / DestBase%
Number2$ = MID$(Digits2$, Remainder% + 1, 1) + Number2$
LOOP UNTIL FinalNum& = 0
END SUB