Bigger computers like minicomputers, mainframes, and supercomputers take up large cabinets or even dedicated rooms. These microprocessor based systems were still less costly than time-shared mainframes or minicomputers. Most developers of early mainframes and minicomputers developed similar, but generally incompatible, mail applications. DEC agreed to contribute more than 300 terminals, 1600 microcomputers, 63 minicomputers, and five employees. Other companies began to offer commercial versions of Unix for their own minicomputers and workstations. It is implemented by central processing units (CPUs) and microprocessors used in PDP-11 minicomputers. Those selling advanced minicomputers were overtaken by the microcomputer. Ericsson Information Systems made Alfaskop terminals, typewriters, minicomputers and Ericsson-branded IBM compatible PCs. It became important again on the initially-tiny memories of minicomputers and then microprocessors. These range from VAX minicomputers to Pocket PC PDAs. Early SCADA system computing was done by large minicomputers. Around 1970, Digital Equipment Corporation donated two small rackmount PDP-11 minicomputers. Besides motherboards, ASRock also sells desktop minicomputers. It was used with IBM AS/400 minicomputers. During the 1970s Olivetti manufactured and sold two ranges of minicomputers.