Extending the Addressing Capabilities of the IBM Series/1 to 32 Bits
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
A technique is described whereby the total logical addressability of the IBM Series/1 is extended from 20 bits (1 megabyte) to 32 bits (4 gigabytes). The extension divides the total two gigabytes of addressing capability into 256 address spaces, each having an addressing capability of from two kilobytes to 16 megabytes. The technique described herein allows the current 16-bit IBM Series/1 to not only support existing software programs, but to enable new software programs having 24-bit addressability to run concurrently with the current programs. In addition, the concept supports all existing input/output attachments. The extension supports 16 megabytes of real storage, all of which can be addressed using real, non-translated addresses.