Operating System (OS)
The instruction register

None of these
is a hardware memory device which denotes the location of the current instruction being executed.
is a group of electrical circuits (hardware), that performs the intent of instructions fetched from memory.
contains a copy of the designated memory location specified by the MAR after a "read" or the new contents of the memory prior to a "write".
contains the address of the memory location that is to be read from or stored into.

ANSWER DOWNLOAD EXAMIANS APP

Operating System (OS)
Addressing structure

All of these
performs indicated operations on two fast registers of the machine and leave the result in one of the registers.
are variations in the use of fundamental addressing structures, or some associated actions which are related to addressing.
None of these
defines the fundamental method of determining effective operand addresses

ANSWER DOWNLOAD EXAMIANS APP