 The rackmount configuration was a pedestal without the plastic covers or casters that fitted in a standard 19-inch RETMA cabinet.Each zone had a five-slot backplane for a KA510 CPU module, one to three 32 MB MS520 memory modules, one or two KFE52 system I/O controller modules and one or two DEC WANcontroller 620 (DSF32) wide area network (WAN) communications adapters.The leftmost slot was the first slot.