David A Randall DeceasedNashua, NH

5388156, Feb 7, 1995

Feb 26, 1992

7/840965

John W. Blackledge - Boca Raton FL
Grant L. Clarke - Boca Raton FL
Richard A. Dayan - Boca Raton FL
Kimthanh D. Le - Boynton Beach FL
Patrick E. McCourt - Delray Beach FL
Matthew T. Mittelstedt - Delray Beach FL
Dennis L. Moeller - Boca Raton FL
Palmer E. Newman - Boca Raton FL
David L. Randall - Pompano Beach FL
JoAnna B. Yoder - Delray Beach FL

International Business Machines Corp. - Armonk NY

H04L 900

380 4

This invention relates to personal computer systems and, more particularly, to such a system having security features enabling control over access to data retained in such a system. In particular, a personal computer system in accordance with this invention has a normally closed enclosure, at least one erasable memory element for selective activation to active and inactive states and for receiving and storing a privileged access password when in the active state, an option switch operatively connected with the erasable memory element for setting the erasable memory element to the active and inactive states, a tamper detection switch operatively connected with the erasable memory element for detecting opening of the enclosure and for invalidating any privileged access password stored in the erasable memory element in response to any switching of the tamper switch, and a system processor operatively connected with the erasable memory element for controlling access to at least certain levels of data stored within the system by distinguishing between the active and inactive states of the memory element and between entry and non-entry of any stored privileged access password. In the presently preferred form of the invention, two non-volatile erasable memory elements are provided, one an EEPROM and the other battery backed CMOS RAM.