Xerox Data Systems Model 940 SDS 940 XDS 940 <computer> (SDS 940, XDS 940) A {time-sharing} system, announced in February 1966, developed by {Scientific Data Systems} with help from The {University of California at Berkeley} and {Tymshare}. SDS 940 was {backward compatible} with SDS's previous systems (except the 12-bit {SDS 92}). It had {monitor} and user modes, dynamic program relocation, automatic memory fragmentation, and system protection. After 1968 {Xerox} bought out SDS and renamed the SDS machines "Xerox Data Systems" (XDS). Xerox then produced the {XDS 530}. (2004-06-17)