David L Ruhberg

US Patent:

46139532, Sep 23, 1986

Filed:

Apr 22, 1983

Appl. No.:

6/487554

Inventors:

John M. Bush - Fort Collins CO
David L. Ruhberg - Fort Collins CO

Assignee:

NCR Corporation - Dayton OH

International Classification:

G06F 1206

US Classification:

364900

Abstract:

An addressing and control system for a mass memory which is partitioned into selectable pages of individually specified size. The invention generates a composite address for the mass memory so that a microcomputer of limited address size can access the mass memory by individually specified page. One circuit implementation utilizes a register to latch page size and selection information for subsequent combination with address information to generate a full address for the mass memory. In that situation, the size register multiplexes the address bus information and page selection information to maintain correspondence between the specified size of the page and the total addressing bits available. In another form, the invention provides for supplementing the number of address bus bits with bits transmitted over the data bus to extend the bit length of the address used to access the mass memory.