• MARIE’s have  seven registers.They  are: 

• Accumulator
• Memory address register
• Memory buffer register 
• Program counter
• Instruction register 
• Input register
• Output register

The Functions of MARIE's Registers :

(1) Accumulator

  Denoted by AC, a 16-bit register that holds a conditional operator (e.g., "less than") or one operand of a two-operand instruction.

 (2) Memory address register

  Denoted by  MAR, a 12-bit register that holds the memory address of an instruction or the operand of an instruction.

(3) Memory buffer register 

   Denoted by  MBR, a 16-bit register that holds the data after its retrieval from, or before its placement in memory.

(4) Program counter

   Denoted by  PC, a 12-bit register that holds the address of the next program instruction to be executed.

(5) Instruction register 

  Denoted by  IR, which holds an instruction immediately preceding its execution.

 (6) Input register

  Denoted by InREG, an 8-bit register that holds data read from an input device.

(7) Output register

  Denoted by  OutREG, an 8-bit register, that holds data that is ready for the output device.