BMS logical messages

The disposition options do not affect the correspondence between SEND MAP commands and pages of output.

You get one page for each SEND MAP command, unless you also use a second feature of full BMS, the ACCUM option. ACCUM allows you to build pages piecemeal, using more than one map, and like PAGING, it allows your message to exceed a page. You do not have to worry about page breaks or about tailoring your output to a specific page or screen capacity. BMS handles these automatically, giving you control at page breaks if you want. Details on cumulative page building are in Cumulative output — the ACCUM option.

As soon as you create an output message of more than one page, or a single page composed of several different maps, you are doing something BMS calls cumulative mapping. PAGING implies multiple pages, and ACCUM implies both multiple and composite pages, and so at the first appearance of either of these options, BMS goes into cumulative mapping mode and begins a logical message. The one-to-one correspondence between SEND commands and messages ends, and subsequent SEND MAPS add to the current logical message. Individual pages within the message are still disposed of as soon as they are complete, but they all belong to the same logical message, which continues until you tell BMS to end it.