>I need a routine (basic, asm, whatever) that can convert a hexadecimal
>string to a hexadecimal number (for calculations).
>Can anyone help me with that? Thanks!

> > BASIC only calculates in decimal (base 10).  You can convert the hex strings
> > to decimal, do the calculations and convert the answer back to a hex string:

> That would be a solution yes. However, the freeware basic compiler I use
> can't convert a hex string to a decimal one that way...:(
> A good hex string -> decimal number would be great too, the trouble is
> the conversion from a hex string to a number (either hexadecimal or
> decimal).

> Comment %

>         String => Number (*HEXADECIMAL* - 64 bit)
>         Input:  ECX     = Length of string 8 (obviously max 8)
>                 DS:ESI  = Pointer to string (numbers A-F must be in uppercase)
>         Output: EDX:EAX (number value of input string)
>         Registers changed: EDX & EAX
>         Flags : none

>          %

> str2hnum PROC
>         pushf
>         push ebx ecx edi esi ebp

>         mov EBP, 10h                    ; EBX =   Upperpart
>         xor eax, eax                    ; init
>         xor ebx, ebx                    ; init

> nextchar:
>         xor edx, edx                    ; EDX=0 - needed ?
>         Imul ebx, ebx, 10h              ; Update upperpart
>         mul EBP                         ; Update lowerpart
>         add ebx, edx                    ; Add "carry"

>         movzx edi, byte ptr [esi]       ; fetch char
>         cmp edi, 40h
>         jl number
>         sub edi,7

> number:
>         add eax, edi                    ; add next char
>         adc ebx, 0                      ; Adjust if carry
>         sub eax, 30h                    ; subtract "char" value

>         inc esi                         ; next letter
>         dec ecx                         ; oneless letter to go
>         jnz nextchar                    ; was it the last?

>         xchg edx, ebx                   ; output is EDX:EAX
>         pop ebp esi edi ecx ebx
>         popf
>         RET

> str2hnum ENDP

>> > BASIC only calculates in decimal (base 10).  You can convert the hex
strings
>> > to decimal, do the calculations and convert the answer back to a hex
string:

>> That would be a solution yes. However, the freeware basic compiler I use
>> can't convert a hex string to a decimal one that way...:(
>> A good hex string -> decimal number would be great too, the trouble is
>> the conversion from a hex string to a number (either hexadecimal or
>> decimal).

>Actually, BASIC generally calculates in binary.  Almost all computer
arithmetic
>is done in binary.  BASIC merely displays and accepts numbers in decimal.
They
>are converted to binary for processing.  Here is a QBasic/QuickBasic
program
>that converts a Hex string to a LONG integer, and prints it in decimal.

>'  **************************************************
>'  *                                                *
>'  *                  HEX2DEC.BAS                   *
>'  *                                                *
>'  *        Convert a Hex Number to Decimal         *
>'  *                                                *
>'  *              Judson D. McClendon               *
>'  *              Sun Valley Systems                *
>'  *              329 37th Court N.E.               *
>'  *              Birmingham, AL 35215              *
>'  *                 205-853-8440                   *
>'  *                                                *
>'  **************************************************
>'
>DECLARE FUNCTION Hex2Dec# (HexNbr AS STRING)
>DIM Nbr AS LONG, HexNbr AS STRING

>CLS
>DO
>   INPUT "Enter Number in Hex (Enter to quit): "; HexNbr
>   Nbr = Hex2Dec#(HexNbr)
>   IF (Nbr < 0) THEN
>      PRINT "Invalid Hex Number"
>   ELSE
>      PRINT "Decimal: "; Hex2Dec#(HexNbr)
>   END IF
>LOOP UNTIL (HexNbr = "")
>END

>FUNCTION Hex2Dec# (HexNbr AS STRING)
>   DIM Nbr AS LONG, Digit AS LONG, P AS INTEGER

>   Nbr = 0
>   FOR P = 1 TO LEN(HexNbr)
>      Digit = INSTR("0123456789ABCDEF", UCASE$(MID$(HexNbr, P, 1))) - 1
>      IF (Digit < 0 OR Digit > 15) THEN
>         Nbr = -1
>         EXIT FOR
>      END IF
>      Nbr = Nbr * 16 + Digit
>   NEXT
>   Hex2Dec# = Nbr
>END FUNCTION
>--
>Judson McClendon          This is a faithful saying and worthy of all
>Sun Valley Systems        acceptance, that Christ Jesus came into the

>(please remove zzz from email id to respond)

> Dec2Hex$ = HEX$(Value#)
> Hex2Dec# = VAL("&H"+Value$)

> >> That would be a solution yes. However, the freeware basic compiler I use
> >> can't convert a hex string to a decimal one that way...:(