support@bingvaxu.cc.binghamton.edu (Academic Support) (06/16/89)
Does anyone know if it's possible to reset the flow control on a vt220 terminal via some control sequence? Ya see, a large number of our students don't know how to use the Setup key to set the flow control on their terminals (yes we have an ample supply of locally written documentation as well as conducting workshops for beginners, but...). The default setup is XON/XOFF to enable the use of the Hold Screen key, as well as allowing the use of slow scroll and local printers, but lately we've been acquiring a growing number of Emacs users who change the flow control to No XOFF. This allows them to use Ctrl-s and Ctrl-q for Emacs stuff. What I'd like to do is have the students' initialization file reset the flow control to XON/XOFF, thus reducing the hysteria of novice users who find that they can't stop their screen from scrolling. I haven't been able to locate a Programmer's Reference Manual, but what I've seen in the Owner's Manual hasn't been too encouraging. Thanks for any help you can provide.-- ======================================================================== :Bill Hanrahan Relax, don't worry...have a homebrew :Programmer/Analyst SUNY Binghamton :hanrahan@bingvaxu.cc.binghamton.edu hanrahan@bingvaxa.bitnet
leichter@CS.YALE.EDU (Jerry Leichter) (06/22/89)
In article <2196@bingvaxu.cc.binghamton.edu>, support@bingvaxu.cc.binghamton.edu (Academic Support) writes... >Does anyone know if it's possible to reset the flow control on a >vt220 terminal via some control sequence? > >Ya see, a large number of our students don't know how to use the Setup >key to set the flow control on their terminals (yes we have an ample >supply of locally written documentation as well as conducting >workshops for beginners, but...). The default setup is XON/XOFF to >enable the use of the Hold Screen key, as well as allowing the use of >slow scroll and local printers, but lately we've been acquiring a >growing number of Emacs users who change the flow control to No XOFF. >This allows them to use Ctrl-s and Ctrl-q for Emacs stuff. > >What I'd like to do is have the students' initialization file reset the >flow control to XON/XOFF, thus reducing the hysteria of novice users >who find that they can't stop their screen from scrolling. I haven't >been able to locate a Programmer's Reference Manual, but what I've >seen in the Owner's Manual hasn't been too encouraging. Can't be done. -- Jerry
sean@geac.UUCP (Sean Phelan) (06/22/89)
In article <64338@yale-celray.yale.UUCP> leichter@CS.YALE.EDU (Jerry Leichter) writes: >In article <2196@bingvaxu.cc.binghamton.edu>, support@bingvaxu.cc.binghamton.edu (Academic Support) writes... >>Does anyone know if it's possible to reset the flow control on a >>vt220 terminal via some control sequence? >>.... >>What I'd like to do is have the students' initialization file reset the >>flow control to XON/XOFF, thus reducing the hysteria of novice users >>... > >Can't be done. > -- Jerry Well, it can be done, but not in isolation. Why not just send a DECSTR "Soft terminal reset" sequence ( CSI ! p ) thereby restoring the power-on settings of the terminal ? For a really rock-solid solution, start your initialisation with RIS, "Hard terminal reset", which is ESC c. Only problem with that is the 1-2 second pause while the terminal does a self-test. Cheers, Sean -- Sean Phelan | "Education furnishes the mind, Geac Computer, Markham, Ontario | making it a pleasant place to sean@geac | spend the rest of one's life" {uunet!mnetor,yunexus,unicus,utgpu}!geac!sean |
gwyn@smoke.BRL.MIL (Doug Gwyn) (06/22/89)
>In article <2196@bingvaxu.cc.binghamton.edu>, support@bingvaxu.cc.binghamton.edu (Academic Support) writes... >>This allows them to use Ctrl-s and Ctrl-q for Emacs stuff. That's a very bad idea. Many terminals require flow control to work properly, especially if there is a sequence of slow operations such as line insert at a high baud rate. Any reasonable EMACS implementation allows you to rebind your search etc. keys (we use ASCII FS in place of ^S) and supports DC3/DC1 flow control (which it should do simply by not disabling flow control if it was set in the terminal handler flags).