IBM 3164 ASCII Manual page 139

Chapter 5. Programming considerations
5-52
A viewport on the screen is defined by the following parameters:
• Dv and Wv specify the depth and width of the viewport, respectively.
• Rv and Cv specify the row and column of the viewport, respectively.
Since Rv and Cv represent offset values, they are one less than the
absolute row and column numbers of the viewport origin. For example, to
place the viewport origin in the top left corner of the screen, you should
specify Rv=O and Cv=O.
The following figure shows the relationship between the viewport and
partition.
Partition-1
~~~-~~
Partition-2
3
Partition-3
& . . - - - '
WindO_W-:3
----J~
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