(PCM) A manufacturer of equipment that some other manufacturer's system can identify and work with. The PCM's device replaces the original manufacturer's. Most PCMs competed with IBM. PCM devices normally offer a cost-performance benefit over the original device. For example, several PCM versions of the Direct-Access Storage Device IBM 3350 offered twice the storage and improved data access (dual port). Plug compatible devices include replacement CPUs, such as the Hitachi 7/90 series (which could be substituted for IBM 3090 series processors), I/O subsystems, and dumb terminals like the IBM 3270.