mfp_send_usart
mfp_send_usart(0x49);
mfp_send_usart(0x49); /* XXX */
mfp_send_usart(0x48); /* XXX */
return mfp_send_usart(*(uint8_t *)addr);
mfp_send_usart(~kbdled | 0x80);
mfp_send_usart(0x41);
int mfp_send_usart(int);
mfp_send_usart(onoff | 0x40);