I used to swear at mine on a regular basis. To no apparent effect. On Tue, Jan 14, 2020 at 12:45 PM Mike Schwab <mike.a.sch...@gmail.com> wrote:
> > https://turnkey-mvs.yahoogroups.narkive.com/YoMvjj8Q/turnkey-mvs-under-vm-and-3270-w-3174 > 3174 with ethernet and token ring. Hercules on PC connected to > ethernet. Apple II with token ring as console. > > On Tue, Jan 14, 2020 at 9:24 AM Charles Mills <charl...@mcn.org> wrote: > > > > Would talking the TN3270 protocol to a 3270 emulator do the job for you? > > That solves all of the hardware issues: it is simply TCP out of your > > implementation and into the emulator. > > > > You could then if you wished "graduate" to a real 3270 terminal. If I > were > > doing it I would go SNA but that is because once upon a time I knew SNA > at > > the bit level, but little about how bus & tag worked at that level. > > > > I can't speak much to physical connection or the layer immediately above > > that but this book http://ruelgnoj.co.uk/3270/3270.pdf is the bible of > the > > byte stream going to the device. > > > > There is no real reason you could not drive one from Linux or Windows. A > > Raspberry Pi with a 3270 attached would be an amusing idea. > > > > BTW, RS232 is a specification for the plug between a device and a modem. > It > > is at a lower level in the stack than most of the other things you > mention. > > Yes, it would be relevant to a dial-up SNA implementation. The "bits > going > > over the modem" layer of SNA is called SDLC > > (https://en.wikipedia.org/wiki/Synchronous_Data_Link_Control). > > > > Good luck! Sounds like fun. > > > > Charles > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > > Behalf Of Alexander Huemer > > Sent: Tuesday, January 14, 2020 1:52 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Talking to 3270 terminals? > > > > Hi > > > > I am new to this list and would like to discuss an idea and ask several > > questions. > > > > * Did anybody ever attempt to 'talk' to 3270 terminals with something > > different than an IBM mainframe? > > > > This might sound like a strange idea, though I find it intriguing to be > > able to display content on such a terminal and be able to receive > > keyboard input from it. > > > > I guess the most straight-forward way to attempt something like that is > > to use a 3270 terminal attached to a 3174 or similar and try to talk to > > that instead of the terminal itself. I wouldn't know how to interface > > with the terminal directly over the coax. > > > > * What's the best available documentation regarding 3174 models and > > their features? > > > > I poked around on ibm.com and google but wasn't able to find much. It > > seems like there were several different physical-layer north-bound > > interfaces for 3174. Bus&Tag, Token Ring, Ethernet, RS232 (if I am not > > mistaken, for dial-up connections), maybe others? > > > > Bus&Tag doesn't seem to be a good candidate, it's difficult to interface > > with as far as I understand. > > Ethernet is way more common these days than Token Ring, though TR NICs > > are easy to procure second hand and protocol support under Linux (the OS > > I am most savvy with) is in place. > > RS232 is easy to interface with also, though then again, I am not sure > > if that interface really exists. > > > > * Did the LAN interfaces (Ethernet, TR) talk SNA on layers 2 and 3 or > > was there by any chance something going on with TCP/IP? I doubt it > > though. > > > > Talking SNA with custom software doesn't seem to be a low-hanging fruit. > > From where I stand right now I cannot say how straight-forward the > > network traffic between the mainframe and a 3174 is, how difficult it > > would be to emulate that protocol with custom software over several > > layers. > > > > * Is anybody on the list here able to provide protocol traces from the > > link between mainframe and 3174 over any interface? pcap format is > > preferred, though anything would be valuable. > > > > I would appreciate any thoughts regarding this topic, especially to the > > questions marked with asterisks. > > Also, if anything is known regarding a similar thing with 5250 instead > > of 3170 terminals, that would be interesting as well. > > > > -Alex > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > -- > Mike A Schwab, Springfield IL USA > Where do Forest Rangers go to get away from it all? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > -- zMan -- "I've got a mainframe and I'm not afraid to use it" ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
