12 Introduction
Screen Display and Pages
This terminal offers a variety of screen lengths including 26, 30, 44, or 52 lines. These numbers include the top and bottom status lines (or label line), as well as the lines used to display data. A “page” of terminal memory represents the total number of lines that can be accessed, whether or not they are all viewable on the screen at once. Refer to Appendix A for the number and lengths of pages available for your setup.
The page length is comprised of a base page length multiplied by 1,2,4, or 8. For instance, in certain modes, 24 (24x1), 48 (24x2), and 96 (24x4) are available, the same way that 25(25x1), 50 (25x2), and 100 (25x4) are. The base page length and the screen size determine whether a bottom status line or label line is displayed or not.
Bottom Status/Label Line Display
With a screen length of “26 lines,” the page lengths that are multiples of 24 allow the bottom status/label line to be displayed, while those that are multiples of 25 do not. The same idea applies with the 44 line screen size. A page length with 42 lines as a base page size will display a label line, while the 43 line base page length will not. An exception to this rule is if the screen length is significantly larger than the that page size, then the label line will be displayed, such as if the screen is 44 lines and the page length is 25 lines.
Viewports
Up to three viewports can be selected on a page. Each viewport has its own character attribute, cursor position, field attribute propagation, tab stops and scrolling region. All of the viewports are displayed on the same screen and can be partitioned with a visual separator line. If the keyboard is associated with one viewport and the host is associated with another, it is possible to receive data in two viewports simultaniously.
