a$.$ On a typical microprocessor, there is a direct port addressing capability, in which a $16-$ bit port address is part of the instruction, and an indirect port addressing capability, in which the instruction references one of the $16-$bit general purpose registers, which contains the port address. How many ports can the microprocessor address in each $1/0$ addressing mode?

b$.$ A particular system is controlled by an operator through commands entered from a keyboard. The average number of commands entered in an $6-$hour interval is $80.$ Suppose the processor scans the keyboard every $100$ ms$.$ how many times will the keyboard be checked in an $6-$hour period?

c$.$ Let DS$-3080$H$,$ CS$=0000$H$,$ SI$=0008$H and IP$=00$FFH$.$ What is the physical address of the instruction and data that is fetched?

d$.$ How many Memory chips of size $512$K X $8$ are needed to develop a memory of size $8$M X $32.$ Show the address range.