Mainframe, MVS and zOS Discussion

Hi,

I am working on COBOL CICS program and it has the following message:
I tried to find some combination of it in https://www.google.com/search?q=80+byte ... CAc&uact=5 but I did not get a good document to understand it. Can someone please guide me why do we need two different BYTE version of same CIC MAP?

3270 terminals come in a variety of sizes -- 24 lines by 80 columns, 43 lines by 132 columns, and so forth. Since the CICS mapset is based upon the terminal size, displaying a 24x80 screen on a 43x132 terminal means the data is offset and very difficult to read or navigate through. So having multiple maps allows the program to work with different terminals in the system.

Thanks. I did not know this. If it is so and there is a company which is working on with all type possible terminals then how many MAPS of these natures will they create?

And where do we tell system that which map to use when?

Normally, a company will go with a few standard terminal sizes so maps don't have to be developed for every possible terminal. It is not unusual for applications to use different transactions for different terminal sizes (which is one way to distinguish them; another way is to use EXEC CICS INQUIRE TERMINAL). It also is not unusual for companies to decide to use a single terminal size for all their CICS terminals. The determination of which map is sent is made when the EXEC CICS SEND MAP command is issued.