Sub-System was redesigned to use the improved Z180 microprocessor (the Buffer Controller card, Programmable Line Controller card and two Communication Line Interface cards were incorporated on to a single card). The XN20 was in pre-production stage when the Communication Systems Division was shut down in 1992. Jack Ralph was the chief architect of the Cyber 1000-2, XN-10 and XN-20 systems. Dan Nay was the chief engineer of the XN-20. Cyber 2000 See also CDC 6000 series — contains several predecessors to the Cyber 70 series Notes References External links CDC IBM front end bows (Article in Network World Dec 1, 1986, page 4) Cyber documentation at bitsavers.org Cyber Supercomputers Control Data Corporation mainframe computers