Specifications

SECTION III
3.3.3 Customizing Scrolling
Ordinarily, the area of the screen in which data scrolls is the entire 24 rows; and the lines of
memory in which data scrolls is the current page. For example, if the cursor is on page 2
when lines per page is 48, then the scrolling area of memory is lines 49 through 96.
Scrolling can be customized in two ways. One way, defining a scrolling region, is used to
restrict the area of the screen, and the related area in memory, in which data may scroll.
The other, locking lines, is used to exclude from scrolling certain rows of the screen, and
their associated lines in memory.
NOTE: Customized scrolling applies only to the page on which it is set-up. E.g., if you
customize scrolling on page 1, page 2 may scroll in the usual way.
NOTE also: When scrolling is customized, cursor addressing is relative to the customized
area. For example, if a scrolling region has only 10 lines, the last line of the region is the
tenth line.
NOTE therefore
Customizing scrolling when the lines/page is 48 or 96 is NOT
recommended.
3.3.3.1 Defining a Scrolling Region
Defining a scrolling region simultaneously restricts scrolling
to a particular area of the screen
to a particular area of memory.
Any block of adjacent rows of the screen may be defined as the scrolling region. The
associated lines in memory, i.e., the lines appearing in those rows when you define the
region, determine the scrolling region of memory. In effect, it determines what lines of
memory sijiside the scrolling region remain visible. (See Figures 3-6.)
To define a scrolling region, enter the sequence
ESC A B
where A top row of the screen scroll region (in ASCII) (see Appendix G)
B bottom row of the screen scroll region (in ASCII) (see Appendix G)
To reset scrolling to the full screen and the entire page, enter the sequence
ESC _ space 7
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