Browse Prior Art Database

Support for Extended Display Attributes On an IBM 5250 Display

IP.com Disclosure Number: IPCOM000119585D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 87K

Publishing Venue

IBM

Related People

Hovland, KJ: AUTHOR [+2]

Abstract

This article describes extensions to 5250 display data stream architecture to allow extended attributes to be written, erased, and read from a 5250 work station which supports extended attributes. Extended attributes are written behind the display screen and do not require a screen position. Extended attributes can specify highlighting (for example, reverse image or intensify), color, single/double byte mode for Kanji, etc. Two new Write to Display orders, a new 5250 read command, and minor enhancements to existing 5250 data stream processing/5250 keystroke processing provide this function. The flow of 5250 data stream between a host processor and a Work Station Controller (WSC) is shown in the figure. The WSC can communication with the host either across a communication line or a system bus.

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Support for Extended Display Attributes On an IBM 5250 Display

      This article describes extensions to 5250 display data
stream architecture to allow extended attributes to be written,
erased, and read from a 5250 work station which supports extended
attributes.  Extended attributes are written behind the display
screen and do not require a screen position.  Extended attributes can
specify highlighting (for example, reverse image or intensify),
color, single/double byte mode for Kanji, etc.  Two new Write to
Display orders, a new 5250 read command, and minor enhancements to
existing 5250 data stream processing/5250 keystroke processing
provide this function.  The flow of 5250 data stream between a host
processor and a Work Station Controller (WSC) is shown in the figure.
The WSC can communication with the host either across a communication
line or a system bus.

      WRITE EXTENDED ATTRIBUTE (WEA) ORDER:  The new WEA order
(X'12') under the 5250 Write to Display data stream command allows
one extended attribute to be written behind any screen location, as
pointed to by the current display address (set with the Set Buffer
Address order).  The WEA order is followed by two parameter bytes:
the attribute type (highlighting, color, single/double byte mode for
Kanji, etc.)  and the extended attribute.  A single extended
attribute can specify multiple attributing effects (for example,
intensify and blink).  Attributing effect begins at the position of
the extended attribute and propagates until a nonzero extended
attribute is found.  For each WEA found in the 5250 data stream, the
WSC will send a write command to the 5250 work station containing the
attribute type and extended attribute.

      ERASE TO ADDRESS (EA) ORDER:  The new EA order (X'03') under
the 5250 Write to Display data stream command allowed extended
attributes to be erased without having to initialize the entire
display screen.  The EA order is followed by parameters:  row and
column values which indicate the ending point of the erase, a length
byte and associated list of extended attribute types to be cleared
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