mul24

static int carry;
uint16_t mul24(uint16_t in16, uint8_t in8)
{
    uint8_t h = in16 >> 8;
    uint8_t l = in16 & 0xff;
    uint16_t mh = (uint16_t) in8 * h;
    uint16_t ml = (uint16_t) in8 * l;
    uint16_t r = 0;
    if (mh & 0xff00) {
        carry = 1;
    } else {
        carry = 0;
        r =   mh;
        r <<= 8;
        r +=  ml;
    }
    return r;
}