Determine the registers are available in machines

Typical registers, some of which are commonly available in machines.

These registers are as follows:-

• Memory Address Register (MAR):- Connected to address lines of the system bus. It specifies address of memory location from where data or instruction is to be accessed (for read operation) or where the data is to be stored (for write operation).
• Memory Buffer Register (MBR):- MBR connected to data lines of the system bus. It specifies which data is to be accessed (for read operation) or to which data is to be stored (for write operation).

• Program Counter (PC):- Holds address of next instruction that has to be fetched, after execution of an on-going instruction.

• Instruction Register (IR):- Here instruction is loaded before their execution or holds where last instruction fetched.