NAME
        ReadExpansionByte - read a byte nybble by nybble.

   SYNOPSIS
        byte = ReadExpansionByte( board, offset )
        D0                        A0     D0

   FUNCTION
        (Not typically called by user code)

        ReadExpansionByte reads a byte from a new-style expansion
        board.  These boards have their readable data organized
        as a series of nybbles in memory.  This routine reads
        two nybbles and returns the byte value.

        In general, this routine will only be called by readexpansionrom.

        The offset is a byte offset, as if into a expansionrom structure.
        The actual memory address read will be four times larger.
        The macros EROFFSET and ECOFFSET are provided to help get
        these offsets from C.

   INPUTS
        board - a pointer to the base of a new style expansion board.
        offset - a logical offset from the board base

   RESULTS
        byte - a byte of data from the expansion board.

   EXAMPLES
        byte = ReadExpansionByte( cd->BoardAddr, EROFFSET( er_Type ) );
        ints = ReadExpansionByte( cd->BoardAddr, ECOFFSET( ec_Interrupt ) );

   SEE ALSO
        writeexpansionbyte(), readexpansionrom()