Patent · US Expired

Data processing system write protection mechanism

US4432050A · kind A · utility

14Cited by
8References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 1, 1980
Grant dateFeb 14, 1984
Priority date
Expiry dateOct 1, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/24
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Use of a control storage device coupled with a central processing unit is locked, during the loading process from the unit to the device, to a would-be user of the device until such loading process is complete as indicated by a so-called "unlock" command received from the central processing unit. An indication of an error or malfunction in the control storage device either during the loading process or thereafter is also provided to the central processing unit.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.