(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}. [Used outside mainframe market?] (2003-06-24)