It depends on the software that you're using. I'll addres ISPF on z/OS because I'm more familiar with that than, e.g., z/VM.
Worst case the data stream is subject to translation on the MVS side by both ISPF and VTIOC (TSO/VTAM IOC), both allowing the user to control the translation. On the PC side you also have page table issues; the details depend on which TN3270 code page you're using. For upper case A it's pretty easy; the common code pages share code points '20'X through '7F'X with ASCII. But for Logical Not (¬, '5F'X) the client might use either 'AA'X or 'AC'X even if UTF-8 isn't in play. Peter: does ISPF bypass VTIOC translation? ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of [email protected] <[email protected]> Sent: Tuesday, October 10, 2023 12:18 PM To: [email protected] Subject: TN3270, EBCDIC and ASCII Hi! I want to understand how TN3270 emulation works regarding convertion of characters (between EBCDIC and ASCII, and viceversa). This is how I think it works (more or less), but I am not sure at all. So please let me know about any mistakes. Let suppose that you use a TN3270 emulator program to access the ISPF browser to display a dataset. Let also assume, to simplify, that it contains just a single character, an "A".In DASD, what is indeed stored is X'C1' or, to be more accurate, BINARY'1100 0001'. When you BROWSE the dataset, then the Mainframe sends to the TN3270 PC client exactly X'C1' (BIN'1100 0001'). No convertion is done at the Mainframe side. Then, when the TN3270 client receives X'C1', because it knows that this is a TN3270 session and that its configured CODEPAGE is say 500, it realizes that X'C1' corresponds to an "A" displayable character. And, before sending the instruction to display it on the PC screen, it converts X'C1' to X'41'. Is this more or less how this works? Thanks in advnace for your help, Juan Mautalen ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
