Holds next instruction to be executed

$1234567$

Holds memory address of data being referenced

$1234567$

Holds data the CPU needs to process

$1234567$

Holds interrupt signals

$1234567$

Holds address of next instruction to be executed

$1234567$

Holds data just read from memory

$1234567$

Holds data written from the keyboard

$1.$

Memory Buffer Register

$2.$

Accumulator

$3.$

Instruction Register

$4.$

Program Counter

$5.$

Memory Address Register

$6.$

Input Register

$7.$

Flag Register