John I assume we're talking about accessing z/OS 3270 applications using a TN3270 emulator client to a z/OS Communications Server (CS) IP TN3270 server.
When the TN3270 server was first provided in the early '90s in TCP/IP for VM or MVS (as an "internal" server - although "client" to the main address space, hence INTCLIEN), the only access was via the "TELNET solicitor" panel - assuming a session wasn't established by default using DEFAULTAPPL. The selected mode table entry name, mode name, depended on the TELNETDEVICE statements in the TN3270 portion of the PROFILE data set. These took what RFC 2355 calls the "device-type" agreed during TELNET negotiation and the "device-type" mapped to a mode table entry name. With the advent of TN3270E support, the selected name depended on whether or not TN3270E was agreed during TELNET negotiation. In the TELNETDEVICE statement, the left-hand name was the one for use if TN3270E was *not* agreed and the right-hand name was the one for use when TN3270E was agreed. Whatever was not specified by TELNETDEVICE statements was taken from the default TELNETDEVICE statements listed in the z/OS CS IP Configuration Reference. When Unformatted System Services (USS) support was provided, an alternative to relying on this mapping from the "device-type" became available. If no mode table entry name is specified in the USS LOGON command - sometimes loosely called a VTAM command, the TELNETDEVICE selection mechanism applies. If a mode table entry name is specified in the USS LOGON command, the TELNETDEVICE selection mechanism is replaced by the specified mode table entry name name. That is what has applied in your experience and it is what applied in Tom Marchant's experience in his post in the parallel thread, Screen size (was 3270 emulator cost), which now seems to be dealing with the identical topic! However, it is not only the *ability* to be "queryable", as indicated by the X'80' bit, often called the "query" bit, in the second byte of the presentation services field of the BIND image, "queryable" meaning the possibility to use the Read Partition-Query exchange, but the *incentive* to use that exchange which is important. Assuming you are using a TN3270 client capable of supporting TN3270E - as surely all such clients do these days - then you must, in fact, already have been selecting by means of the TELNETDEVICE statements - assuming you are using the specifications on the default statements - a mode table entry with the "query" bit on - no matter which of the "device-type" codes your TN3270E emulator presented during TELNET negotiation. The code will necessarily have been one of the SNX3270x series. In order to suggest to the 3270 application that it uses the Read Partition- Query exchange in order to discover the presentation space dimensions, the *incentive*, the mode table entry needs to have X'03' as the penultimate byte of the presentation services field. The mode table entries from the supplied table D4C32XX3 and D4A32XX3 - as mentioned in later posts - possess both the required specifications in the presentation services field: the X'80' bit in the second byte *and* the X'03' in the penultimate byte. Thus a private mode table entry - in a private mode table I would expect and hope - is not actually necessary. Nevertheless, if you would be so kind as to post the source of your mode table entry named SNA3270Q, we will be able to verify that practice follows theory - or I'll have to redon my thinking cap! Chris Mason On Wed, 25 Feb 2009 13:17:22 -0600, John McKown <[email protected]> wrote: >I have a 43x162 working here on z/OS 1.10. However, to get it, I had to >specify a "queryable" logmode in my VTAM command which connected to the >system. E.g. > >tso logmode(sna3270q) > >where we created a logmode called SNA3270Q which has the query bit on. When >I didn't do this, I got a mod5 screen. > >-- >John ---------------------------------------------------------------------- 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
