On Wednesday, 03/31/2010 at 06:47 EDT, Richard Troth <vmcow...@gmail.com> wrote: > ICC also doesn't support NOHOLD for DISCONN and LOGOFF like some other > "real 3270s" and like LDEV. That's a whole nutha discussion.
ICC has no idea that you have logged off. Unlike 3270 printer sessions, there is no provision in the display data stream for an EOF marker to tell the telnet server that the host is finished. And if there were, we'd have to provide a TERMINAL LOGOFF HOLD|NOHOLD command to control it since 50% of you would hate it either way. (I wish I had that already; I always LOGOFF HOLD.) > But ... does PCOMM not have an immediate PA1? (I'm not used to an > ATTN sequence for PA1.) You wouldn't get the trace, but you'd get > control. > > There's also the trick, I think I learned from Alan Altmark, of > putting the cursor back one position from the start of the command > line then <Enter> for a VM READ. It's a hack. (IMHO) Your 3270 > emulator may affect the viability of this behaviour. You MIGHT then > be able to TS. Alan? Wanna clarify this? You're right that TN3270E doesn't behave like a real 3270, particularly in the area of Attention processing. A 3270 control unit can do whatever it wants to get the host's attention . With TN3270, the client is at the mercy of (a) the protocol, (b) the telnet server implementation, and (c) the interface the telnet server uses to create sessions. I have to contradict Kris: TN3270 doesn't have an ATTN function for non-SNA emulation (as is done by VM and ICC). This is why the backspace-and-press-enter "hack" was invented; it provides the old-school 3215 ATTN function in a "new"-school 3270 environment. Oh, and the RFCs require a telnet server to ignore any telnet IP (Interrupt Process) commands it receives on a TN3270 session. IMO, the 3270 architects did us a disservice by not providing ATTN for non-SNA connections. So while pressing the RESET key unlocks the keyboard, there's nothing the TN3270 client can do to get the telnet server's attention. The ATTN hack doesn't work in the fullscreen app since CP isn't doing the 3215-3270 conversions. Therefore, if you're in a fullscreen app that has issued TERM BRKKEY NONE, then you can easily find yourself trapped (as the author intended?) in the app unless you have outside help (e.g. CP MSG/WNG or DISC/LOGON). If you have SET RUN ON, the DISC/LOGON sequence won't help. If you can get the console into line mode, then you *may* be able to get out. It depends on how creative (annoying) the app was. But as long as you're in fullscreen, you're stuck. Alan Altmark z/VM Development IBM Endicott
