In the computer, associative memory is a set of flip flops along with extra circuitry that enables each word to be compared at the same time. Instead of an MAR, an associative memory has only an MBR and a mask register. When the read signal is given, the associative memory compares the MBR to every word in the memory all at once. If the contents of the MBR is found, a signal is emitted saying so.

Usually, only part of the MBR is compared, which is the purpose of the mask register. If the part of the MBR corresponding to 1's in the mask register is found anywhere in the memory, the entire word is copied into the MBR. To write to the associative memory, a value is put into the MBR and a write signal is given. The associative memory selects a word of its memory at random and copies the contents of the MBR into it.