http://www.postbulletin.com/magazine/2004/08/index.shtml http://www.postbulletin.com/magazine/2004/08/index.shtml "According to Bob Dubke, the second engineer

http://www.postbulletin.com/magazine/2004/08/index.shtml http://www.postbulletin.com/magazine/2004/08/index.shtml "According to Bob Dubke, the second engineer on IBM's 5100 team in Rochester (who now co-owns a locally-based company called eXport Ventures Corp. and also works for Edina Realty), that secret function was his contribution to the design of the computer. The function, which IBM suppressed because of worries about how their competition might use it, was an interface between the assembly code surrounding the computer's ROM exterior, and the 360 emulator hidden beneath it. (IBM declined to comment for this story.) The 5100's emulator gave programmers access to the functions of the monstrous, and much less portable machines, that IBM had produced during the 1960s. An imprint of a hook on the outside of the 5100 symbolized the ability of Dubke's interface to drop into what Titor called "legacy code," and scoop out any necessary operating instructions."