Patent · US Expired

Cassette type semiconductor memory device

US4587640A · kind A · utility

36Cited by
1References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 9, 1983
Grant dateMay 6, 1986
Priority date
Expiry dateNov 9, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C5/143
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A cassette type semiconductor memory device is provided with a RAM and a back-up battery within a cassette, with a connector connected to the main frame of a data processor. The RAM and its periphery circuit, as well, are backed up by the battery. The live-line insertion/removal of the memory pack is detected by monitoring the power source voltage. At this time, memory access is prohibited. Further, flow of current from the main frame into the power source line is prevented.

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