Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!RICEVM1.RICE.EDU!TROTH From: TROTH@RICEVM1.RICE.EDU (Rick Troth) Newsgroups: comp.lang.asm370 Subject: (none) Message-ID: <9003122231.AA00613@lilac.berkeley.edu> Date: 12 Mar 90 21:40:40 GMT References: Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: IBM 370 Assembly Programming Discussion List Distribution: inet Organization: The Internet Lines: 25 On Wed, 7 Mar 90 12:37:19 GLT Bill Vlachoudis said: >Hi, does anyone knows any smart|small algorithm, how to get >the 3270 buffer address codes from Row and Column? Sure, you have to know the width of the screen in characters. Typically it's 80, but on a "model 5" it'll be 132. The 3270 is presented to the application as a buffer. The size of the buffer suggests its model number and therefore its geometry: Model 1 12x40 480 bytes (not supported by VM) 2 24x80 1920 2A 20x80 1600 (not supported for LDEVs) 3 32x80 2560 4 43x80 3440 5 27x132 3564 Issue a "Read Buffer" I/O command to the tube, and you'll get back at least as many bytes as the buffer contains. From that number, you can make close assumptions about the dimensions of the screen. Of course "Sense ID" would be better, but older tubes and control units don't support that command. Rick Troth ------------- Rice ONCS VM Systems Support