void send_char(int ch){
    int status = *(uart_1 + 2); /* read status from 0x888 */
    int txready = 0; /* initiallize TxReady as 0 */
    /* Blocking I/0 */
    while(!txready){  /* loop until TxReady = 1 */
        txready = status & UART1_TRANSM_BIT;
    }
    /* When this is reached, TxReady = 1 */
    *(uart_1 + 1) = ch & 0xff; /* send the lowest byte */
    return;           /* and then return! */
}