.MODEL  medium

        .CODE

; Hard wired for ^16+^15+^2+1, "CRC-16"

        PUBLIC  _add2CRCESPa
_add2CRCESPa     PROC

        ARG     newData:BYTE, oldCRC:WORD
        push    BP
        mov     BP,SP

        push    DX

        mov     AX,[oldCRC]
        xor     DX,DX
        xor     AL,[newData]
        xchg    DH,AL
        xchg    AL,AH
        jpe     genskp

        xor     AX,0C001H

genskp: shr     DX,1
        xor     AX,DX
        shr     DX,1
        xor     AX,DX

        pop     DX
        pop     BP

        ret

_add2CRCESPa    ENDP

        END