Physical paging of output messages
A logical page can be defined to consist of one or more physical pages. Physical paging allows data from a logical page to be displayed in several physical pages on the device. Physical page assignments are made in the format definition. For display devices, the size of a physical page is defined by the screen capacity (the number of lines and columns that can be referred to). For most printer devices, a physical page is defined by the user-specified page length (number of lines) and the printer's line length.
For SLU P (DPM-An) or ISC subsystems (DPM-Bn), a physical page is defined by the user-specified paging option and the DPAGE or PPAGE statement specifying device pages or presentation pages. Physical paging allows data from a message to be transmitted to the remote program or subsystem in several presentation pages or logical pages.
Typically, a logical page has just one physical page. Multiple physical pages per logical page are generally only used when the logical page is designed for a large screen but is also to be displayed on a small screen device. The physical pages can have a totally different format from the pages defined for the large screen device. The following figure illustrates the use of physical paging with a message that creates one physical page on a 3277 model 2 or on a 3276/3278 with 24×80 screen size.
