Kirk Thanks for confirming that my guess that "Attn" would work for Ed is correct.
I'll confess that I missed out the BID angle since my post was quite long enough already. In my description of the way the "change direction" (CD) indicator works, I had assumed that the LU type 2 session was already "in brackets" and hence was observing the strict half-duplex protocol. I've not come across the expression "get direction" before. For those who have to work harder to follow our jargon, this appears to mean "be granted the permission to send a message". Having mentioned the bracket protocol, perhaps one can say that, although "between brackets" is no longer the strict half-duplex environment created when "in brackets" is in effect, there is still a sort of half-duplex situation applying. "Between brackets", the secondary LU (3270 display) has permission to send, has "got direction", up to the time that the primary LU (application) may send the approximate equivalent of the SIGNAL request, the BID request, and the secondary LU has responded positively. Necessarily, the first message sent when in the "between brackets" state must initiate a bracket by sending the "begin bracket" indicator in the header. You also reminded me that it's only the primary LU which can decide to terminate the "in brackets" state, reverting to the "between brackets" state, by sending the "end bracket" indicator in the header. Chris Mason ----- Original Message ----- From: "Kirk Talman" <[EMAIL PROTECTED]> Newsgroups: bit.listserv.ibm-main To: <IBM-MAIN@BAMA.UA.EDU> Sent: Tuesday, 26 September, 2006 12:45 AM Subject: Re: SDSF Question > It's been +10 yrs since I worked on TPX as a developer, but the behavior > you describe is the difference between SNA and non-SNA protocol. Under > SNA protocol ATTN replaces PA1, because RESET will not unlock the keyboard > and give you direction if the application has not already given it to you, > or ended the bracket so that you can use implied BID to get direction. > > Today I use Extra and (ughh0 Switch, and they use the SNA protocol, > probably under DFT protocol. I use ATTN to get direction when I don't > have it. > > IBM Mainframe Discussion List <IBM-MAIN@BAMA.UA.EDU> wrote on 9/22/2006 > 11:39:24 PM: > > > 10+ years ago we had a vtam appl switcher (sorry forgot the name but > > it could have been TPX). > > > It worked great on real 3270's but they made us switch over pc's. The > > 3270 emulator would not let us hit reset and pa1 . It essentially > > made the vtam appl switcher unusable. grumble grumble I complained > > but no one would listen. I suggested dropping the product as it was > > useless now. The VP of the PC department got p-oed. We had a meeting > > and when I showed up with VTAM traces to prove his emulator wasn't > > working correctly he got even madder. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
