3 ms·

Sometimes I fantasise about implementing a BBS, which only offered connections over tn3270 and tn5250. Nothing impossible about it – they are both just protocol

Sometimes I fantasise about implementing a BBS, which only offered connections over tn3270 and tn5250. Nothing impossible about it – they are both just protocols, and ASCII-EBCDIC conversion is trivial (I once wrote my own implementation of UTF-EBCDIC in Java – utterly pointless exercise, never had a practical use for it, but it was fun.) I suppose only supporting 3270/5250 would be a bit of a barrier to entry that might make it a bit different from something more easily accessible. And it would be cool to connect a real 3270/5250 etc to it. To be as real as possible, you'd probably want a controller like a 3271/3274/3174 (for 3270), and then a BSC or SDLC connection to an IP converter; I don't think 5250 terminals had controllers (edit: no I'm wrong, they did, like the IBM 5394 and 5494), but I believe some of them could be connected through SDLC as well. But I don't have space for it and hardware isn't really my thing. Not that I have time to make my purely software-based 3270/5250 fantasies come true either. Well, maybe some day.

rbanffy 4y ago
You can do it with Hercules, but then you'd be programming on a vintage mainframe (unless you ignore licensing and run zOS on it, and deal with IBM's legal dept). There were a couple (literally, two) BBSs in Brazil that supported Minitel terminals (and v.23), which were somewhat ubiquitous in São Paulo. Minitel terminals, much like 3270's and 5250's, don't scroll, and all of the UI for those was page-oriented (most of the time, limited to paging, but they had a graphical splash screen when it detected v.23 speed).
- skissane 4y ago
  I could do it with Hercules – I've mucked around with TK4- – but I was actually thinking of implementing a TN3270 and/or TN5250 server under Linux. (In Java, Python, Lisp, whatever.) They are just protocols after all, so the server doesn't have to be a mainframe/midrange. In fact, I know some non-mainframe platforms have historically supported 3270 connections – UniKix (formerly known as Sun Mainframe Transaction Processing) is a package for rehosting CICS/VSAM applications on Unix, and it includes a Unix-based TN3270 server. Tandem NonStop supports acting as a 3270 server as well – I think Tandem did that to make it easier to sell into big IBM customers, "you can migrate your apps from IBM to Tandem and keep the same terminals"
  - rbanffy 4y ago
    > and keep the same terminals That's an amazing selling point - real metal 3278's and 3279's were amazingly well built and comfortable to use.

rbanffy 4y ago

You can do it with Hercules, but then you'd be programming on a vintage mainframe (unless you ignore licensing and run zOS on it, and deal with IBM's legal dept). There were a couple (literally, two) BBSs in Brazil that supported Minitel terminals (and v.23), which were somewhat ubiquitous in São Paulo. Minitel terminals, much like 3270's and 5250's, don't scroll, and all of the UI for those was page-oriented (most of the time, limited to paging, but they had a graphical splash screen when it detected v.23 speed).

skissane 4y ago
I could do it with Hercules – I've mucked around with TK4- – but I was actually thinking of implementing a TN3270 and/or TN5250 server under Linux. (In Java, Python, Lisp, whatever.) They are just protocols after all, so the server doesn't have to be a mainframe/midrange. In fact, I know some non-mainframe platforms have historically supported 3270 connections – UniKix (formerly known as Sun Mainframe Transaction Processing) is a package for rehosting CICS/VSAM applications on Unix, and it includes a Unix-based TN3270 server. Tandem NonStop supports acting as a 3270 server as well – I think Tandem did that to make it easier to sell into big IBM customers, "you can migrate your apps from IBM to Tandem and keep the same terminals"
- rbanffy 4y ago
  > and keep the same terminals That's an amazing selling point - real metal 3278's and 3279's were amazingly well built and comfortable to use.