I am aware RS232 is just a low-level protocol, though, if I decide to really spend time on this, I have to interface with a 3174 somehow, low-level. And I wonder which options I have for that, regardless of the higher protocol layer. I am not questioning that they have to be figured out.
What is bitsavers? On Tue, Jan 14, 2020 at 07:59:49PM +0000, Seymour J Metz wrote: > An interface to 3270 displays would be useful only if you had software that > supported 3270 on your platform. Further, is there a real 3270 that is less > expensive than running, e.g., TN3270, on a desktop? > > RS-232-C is just a protocol between a serial adapter and a modem; it doesn't > specify, e.g., control characters, packets, going between the modems. B&T, > Ethernet and TR all specify controls at a higher level. > > Your best resource for 3270 information is probably bitsavers. > > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > > > ________________________________________ > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of > Alexander Huemer <alexander.hue...@xx.vu> > Sent: Tuesday, January 14, 2020 4:52 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 > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
