It depends. FOR REAL 3270 DISPLAYS:
Except for the 3277 generation, each 3270 display has a primary size and a secondary size. TSO normally uses the secondary size if it is 80 wide. ISPF has settings to control what it does. For some displays the sizes are fixed. Starting with the 3180, some displays allow the user to select a virtual model number from 2 to 5, which selects the secondary size of the corresponding 3278 model. Finally, starting with the 3180 some displays allow selecting extended model numbers from 2+ to 5+, which allow VTAM to override the primary and secondary sizes. When you configure VTAM, you define a set of BIND images (see LOGMODE in the VTAM documentation.) Typically the installation will have a LOGMODE with the EDS bit set, meaning that the terminal supports the extended data stream and that VTAM will query the terminal for the screen configuration. Finally, you can define a LOGMODE with a custom screen geometry, for thos terminals that support it; I typically define one with a primary size of 43x80 and a secondary size of 27x132. FOR SIMULATED 3270 DISPLAYS: The details depend very much on the program you're using and how you configure it. Typically you have more flexibility than with a real 3270. FOR TN3270 As with a 3270, you typically have more flexibility than with a real 3270 and the details depend on the particular TN3270 client you're using and on how you configure it. If you are using TCAM, the same configuration principles apply but the details are different. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of Christian Svensson [0000022ad63487ef-dmarc-requ...@listserv.ua.edu] Sent: Monday, December 6, 2021 5:07 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: What determines the effective terminal size? Hi folks, I am trying to go back to basics a bit and figure out some things that I have always treated as magic. Right now it is how a 3270 terminal connected to a z/OS determines the size of the terminal. In this case through OSA-ICC (zBC12, OSA-Express5) and not TCPIP, On systems where I have configured VTAM with TCPIP the terminal size seems to almost always "just work". Let's take a look at an example. I have configured X3270 with model "3279-4-E" and oversize set to "133x60". 1) What does the z/OS VTAM screen look like? Over OSA-ICC: 80x24 Over TCPIP: 80x24 So far so good. 2) What does the TSO screen look like? Over OSA-ICC: 80x24 Over TCPIP: 80x24 Ok, no change. 3) What does the ISPF screen look like? Over OSA-ICC: 80x24 Over TCPIP: 133x60 Oh! But why? I do not know! Also, after I exit ISPF back to TSO, the TSO screen is now correctly filling the full screen! I also note that z/VM's login screen seems to behave similarly. Over OSA-ICC the size seems to be fixed at 80x24, but over TCPIP it follows what I configured X3270 to use. Dialing a z/OS VTAM terminal through the z/OS login screen (connected via TCPIP) seems to result in a 133x60 screen both in TSO and ISPF. However if I ATTACH an OSA-ICC terminal straight to a z/OS guest, ISPF gets 133x60 but TSO only 80x24 - *but only if I reconnect to an existing user session.* If I log out and try to log in again I get IKT00405I "Screen erase caused by error recovery procedure". As you can see I am a mess when it comes to understanding how this all fits together! It seems pretty much random to me, except that TCPIP "almost always works" and OSA-ICC "almost never works". I would love to learn more, but I don't even know where to begin. Regards, ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
