def compute_srec_checksum(srec):
    """
        Compute the checksum byte of a given S-Record
        Returns: The checksum as a string hex byte (ex: "0C")
    """
    data = srec[2:len(srec)]
    sum = 0
    for position in range(0, len(data), 2):
        current_byte = data[position:position + 2]
        int_value = int(current_byte, 16)
        sum += int_value
    hex_sum = hex(sum)
    least_significant_byte = hex_sum[len(hex_sum) - 2:]
    least_significant_byte = least_significant_byte.replace('x', '0')
    int_lsb = int(least_significant_byte, 16)
    computed_checksum = ~int_lsb & 255
    return computed_checksum
