A$)$ On a typical microprocessor, a distinct I$/$O address is used to refer to the I$/$O data registers and a distinct address for the control and status registers in an I$/$O controller for a given device. Such registers are referred to as ports. In the Intel $8088,$ two I$/$O instruction formats are used. In one format, the $8-$bit opcode specifies an I$/$O operation; this is followed by an $8-$bit port address. Other I$/$O opcodes imply that the port address is in the $16-$bit DX register. How many ports can the $8088$ address in each I$/$O addressing mode?$$

B$)$ A microprocessor scans the status of an output I$/$O device every $20$ ms$.$ This is accomplished using a timer alerting the processor every $20$ ms$.$ The interface of the device includes two ports: one for status and one for data output. How long does it take to scan and service the device, given a clocking rate of $8$ MHz$?$ Assume for simplicity that all pertinent instruction cycles take $12$ clock cycles.$$