DEC's memory hardware components initially utilized magnetic core memory for early systems like the PDP-8 and PDP-11. Subsequently, semiconductor RAM, primarily DRAM, became standard. These were typically packaged as plug-in modules or cards, designed for specific bus architectures such as Unibus, Q-bus, VAXBI, and XMI. Later implementations commonly incorporated parity checking or Error Correcting Code (ECC) for data integrity.