Folks, The tn3270 support in Hercules emulates channel attached 3270's not bi-sync so may not be a good source of info. On a local 3270 controller each screen has a unique channel-controller-device address. On a bi-sync device only the line going to the device, additional addressing is required using poll/select sequences...
The total reference book is the Datastreams Programmers Reference. http://www.bitsavers.org/pdf/ibm/3270/GA23-0059-4_3270_Data_Stream_Programmers_Reference_Dec88.pdf This covers most of what you want to know. Chapter 9 covers the differences encountered in a bi-sync environment. If you need to understand the lower level bi-sync and the poll-select protocols, which I think may be what is blocking you at present try this:- http://www.euclideanspace.com/coms/protocol/bi_sync/dlc/index.htm its not wonderful but it may help. Looking at the chapter on 3270's in the VM sysgen might help explain the addressing (it might not)... http://www.bitsavers.org/pdf/ibm/370/VM_370/Release_6/GC20-1801-10_VM370_Sysgen_Rel_6_Jan80.pdf Dave > -----Original Message----- > From: cctalk [mailto:[email protected]] On Behalf Of Guy > Sotomayor Jr via cctalk > Sent: 09 December 2017 01:38 > To: Charles Anthony <[email protected]>; General Discussion: On- > Topic and Off-Topic Posts <[email protected]> > Subject: Re: IBM 3270 controller emulation > > It might be worthwhile to look at the source for hercules (370, 390, z/series) > emulator since that includes support for 3270 terminals through tn3270. It’s > pretty good since I can use actual 327x CUT terminals connected to a 3174 > controller which connects to hercules emulating the mainframe. > > TTFN - Guy > > > On Dec 8, 2017, at 5:22 PM, Charles Anthony via cctalk > <[email protected]> wrote: > > > > I am trying to wire 3270 support into the DPS8/M emulator. > > > > Multics supports 3270 via a bisync connection to the 3270 controller. > > Multics sends commands to the Front End Network processor, which > > (originally) passed the commands down the bisync line to the 3270. > > > > I have a running Multics and running 3270 display emulators using > > tn3270 > > (3270 over telnet), so I need to write the code that maps the Multics > > commands into 3270 controller commands (and vice versa) and manages > > the telnet connections to the 3270 display emulators and maps the > > tn3270 traffic into 3270 controllers. > > > > I don't need to actually implement the bisync communications; the > > controller emulator will be running inside the FNP emulator, but I > > need to express controller responses to Multics in the bisync format, > > as Multics is expecting that the responses arrived over a bisync connection. > > > > The problem is that I have no idea how the 3270 controllers worked; > > I've looked through the bitsavers collection; those documents are > > largely concerned with the displays and tend to treat the controllers > > as 'black boxes' that just do the right thing. > > > > So I am seeking pointers to documentation that will give me a better > > grasp of the controller functionality and/or discussions with someone > > who knows how they work..... > > > > Thanks, > > -- Charles
