Department of Defense Air Force Strategic Automated Command and Control System based IBM Series/1 computers. GAO 16-468
U.S. General Accountability Office
<a rel="nofollow" class="external free" href="http://www.gao.gov/assets/680/677436.pdf">http://www.gao.gov/assets/680/677436.pdf</a> US GAO: Federal Agencies Need to Address Aging Legacy Systems, Figure 8, p. 61