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Data Stream Order Disclosure Number: IPCOM000053004D
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 2 page(s) / 13K

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Johnson, JSM: AUTHOR


This article describes a data stream order.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 2

Data Stream Order

This article describes a data stream order.

The announcement of Programmed Symbols as a feature of both the IBM 8775 and 3279 displays means that new ways of presenting data are now available to a very large number of customers. From now on, more and more emphasis will be placed on the ability of these - and future - displays to display data in easy-to-read pictures, such as pie charts, bar charts and graphs. The data streams required to define these pictures will become longer and more complex as the experience and proficiency of the customers using this feature grow.

One reason for the length of many data-streams containing character graphics even today is the high proportion of Set Buffer Address (SBA) orders in them. This is especially true if the format of the picture contains columns of numbers or boxes or vertical lines, etc.

To reduce the number of SBA orders and therefore the length of the data- streams (enabling them to hold picture data more efficiently), this article describes a new buffer control order, called ``Set Address Mode'' (SAM), for mapped buffer display terminals.

The function of this order is to control the way that the buffer address (set by a previous SBA order) is updated. The only form of address update currently allowed is from left to right wrapping to the next row at the right-hand screen/partition boundary (i.e., Column Increment). This order allows the application program to specify the form of address update to be used. The form specified will be valid until either: another SAM order is encountered (address mode set as specified) or a new data-stream containing a write-type command is received (address mode defaults to Column Increment).

This order is thus modal in nature, similar to the existing Set Attribute order.

The format of this order is shown below: See original.

The flexibi...