----- Original Message -----
From: <hugo@EFFEKT.BIZ>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Wednesday, January 14, 2004 4:16 AM
Subject: [OT:] C to VB conversion


Hi group!

I need to rewrite a relatively simple CRC16 routine from C to VB6. This
should not be a problem if I wasn't a C virgin. I just can't get the
hang of C syntax.
Could someone please have a look at it and point out what I am doing
wrong.

***WARNING***  Untested code ahead ***WARNING***

This code compiles in VB6, but has not been tested:

Dim CRC16Table(0 To 255) As Integer

Public Sub InitCRC16()
    Dim I As Integer, J As Integer, Crc As Integer

    For I = 0 To 255 Step 1
        Crc = I * 256
        For J = 0 To 7 Step 1
           Crc = (Crc * 2) Xor ((IIf(Crc And &H8000, &H1021, 0)))
        Next J
        CRC16Table(I) = Crc And &HFFFF
    Next I
End Sub

Public Function CalcCRC16(ByVal S As String) As Integer

    Dim P As Integer, Crc As Integer

    Crc = &HFFFF
    For P = 1 To Len(S)
        Crc = CRC16Table(((Crc \ 256) And &HFF)) Xor (Crc * 256) Xor
Asc(Mid(S, P, 1))
    Next P

    CalcCRC16 = Crc And &HFFFF
End Function


Bob Ammerman
RAm Systems

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