A SIMM is a type of memory module used in computers from the early 1980s to the early 2000s. It is a printed circuit board on which has random-access memory attached to one or both sides. It differs from a dual in-line memory module (DIMM), the most predominant form of memory module since the late 1990s, in that the contacts on a SIMM are redundant on both sides of the module. SIMMs were standardised under the JEDEC JESD-21C standard.

RAM parity checking is the storing of a redundant parity bit representing the parity of a small amount of computer data stored in random-access memory, and the subsequent comparison of the stored and the computed parity to detect whether a data error has occurred.