To Input Ports

That no input is missed, these instructions should be contained in a loop, with a branch out only when a character is read. To output data to the TTY an INP9, x instruction will again result in the status word being output on the data bus. This time, however, we are interested in bit 0, which will be the TBMT flag transmitter buffer empty . If the TBMT flag is a 1 then the data may be output to the UART for transmission. To do this, an OUT9, x instruction is required. Note that during...