https://github.com/lowobservable/oec
Oh wow, that's remarkable. Shopping for the components to build such an interface already. It's every rather simple to do! I am not considering the 3174 idea anymore and will just try to make this work. On Thu, Jan 16, 2020 at 06:31:19AM -0600, Dave Wade wrote: > >Hi > > > >I am new to this list and would like to discuss an idea and ask several > >questions. > > Hi Alex. I am retired, and haven't worked with mainframes for a long time. > However I own several 3174s and 3270 compatible terminals > (If any in Europe has a spare IBM 3270 it would be nice to have a copy) > I know others have replied so please excuse ant duplications... > > >* 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. > > Well some one has attempted that and details of their work can be found here:- > > https://github.com/lowobservable/oec > > >* What's the best available documentation regarding 3174 models and > > their features? > > > > Well I guess "3174 Introduction (GA27-3850-06)" is a good place to start. > There is a copy of the -00 version in PDF on bitsavers, but as far as I know > the latest version, so the -06 is only available in Bookmanager format from > the IBM Publications Center and it a lot of info missing from the -00 version > > https://www-05.ibm.com/e-business/linkweb/publications/servlet/pbi.wss > > just search for "3174". . You will need the IBM Softcopy Reader to read them > > https://www.ibm.com/support/pages/ibm-softcopy-reader > > >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? > > There is also X.21 as a serial interface > > >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. > > Older CISCO routers are a good way to get many of the older protocols listed > here to a modern system > So I have a CISCO router with Token Ring and Ethernet so a Token Ring 3174 > can connect to my Ethernet LAN > They are also available with Ethernet Interfaces and so can encapsulate SNA > or BiSync into IP > > There is an IBM Red Book on using the 3174 in TCPIP netwowrks on BitSavers. > > http://www.bitsavers.org/pdf/ibm/3174/GG24-4172-0_Using_3174_in_TCP_IP_Networks_Jun94.pdf > > > > > >* 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. > > Normally to an IBM host you talks SNA. Later releases of the software will > also go out on standard Telnet for Unix/ASCII hosts or TN3270 for IBM hosts. > So with my 3174 with Ethernet interface I can connect to both the 4361 at > LCM+L and the DECUS VAX eisner.decus.org. > > >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. > > It has been done, well using IBM software. So connecting a 3174 to a CISCO > then feeding that to a modified Hercules running MVS 3.8J. > > >* 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 don't think any one has needed to dig that deep. Its all well documented. > The 3270 datastream manual is rather over comprehensive but its what goes > across the session. Its also important to remember what goes between the > terminal and the 3174 is very different to what the 3174 send to the host. > This is one reason Mainframes were much more scalable than other > architectures. The 3174 (and 3274 before) takes most of the work of talking > to terminals away from the host. > > >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. > > I know very little about 5250 > > > > >-Alex > > Dave > > ---------------------------------------------------------------------- > 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
