Browse Prior Art Database

Programmable Attribute Register

IP.com Disclosure Number: IPCOM000051234D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Dwire, JD: AUTHOR [+2]

Abstract

The present system is directed to expanding storage capability of a memory for coded information through the expedient of a programmable attribute register. In general, memory storage requirements may be reduced by giving one or more bit positions in an attribute data byte stored in a register two possible attributes instead of the conventional one attribute. Of course, the attributes for any given bit position must be mutually exclusive; i.e., they would never be coexistent in the same attribute application.

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Programmable Attribute Register

The present system is directed to expanding storage capability of a memory for coded information through the expedient of a programmable attribute register. In general, memory storage requirements may be reduced by giving one or more bit positions in an attribute data byte stored in a register two possible attributes instead of the conventional one attribute. Of course, the attributes for any given bit position must be mutually exclusive; i.e., they would never be coexistent in the same attribute application.

In an application involving coded information, there are usually certain attributes associated with the information. For example, in a display environment, the display characters, coded in EBCDIC or some other code form, are stored in the system memory to be used to denote the characters to be displayed on a display device. Associated with each display character are attributes such as reverse video, blank, underscore, cursor, etc. These attributes are usually contained within an incremental addressable memory space, e.g., for a 16-bit word; the low-order 8 bits may contain the EBCDIC coded display character, and the high-order 8 bits may contain the attributes. This scheme allows ease of access to the stored information as the characters and the attributes are conveniently stored in adjacent memory locations. However, if the number of attributes associated with each character should exceed the number of bits reserved in the attribute byte, then increasing the number of attribute bytes for each character wou...