When you get `hung up' in a session it is extremely helpful to know which interrupts or mode change commands that can most effectively get you back to a normal session. Part of developing good skills for working with supercomputers is becoming ``super-killer'' of errant processes. This is particularly true for the IBMNET/TELNET `partial pass-through' when most CMS terminal properties pass through in a top-down hierarchy from CMS to TELNET to UNICOS or any other remote system.
(Esc) , {This press with release Escape-key and press ``comma'' sequence is an alternative interrupt to the `Ctrl-g-g' sequence (which only works with an Academic Network (ADN) connection to CMS), and is usually better for returning to CMS, and UNICOS. Note that the `[Escape-key]' is struck and released and then the `,' comma key is pressed; this pair of pressed keys is the `PA1' interrupt key and works for most terminal configurations; at the `CP' prompt near the bottom of the screen, enter the external interrupt `EXT (CR)', after the ``EXTERNAL INTERRUPT'' message (try `EXT' again if it has not worked) enter `HX' to halt execution, followed by an `telnet [remote] (CR)' to re-enter your prior session; sometimes this works better and simpler than the double `Ctrl-g' sequence; if `(Esc),' does not work try `Ctrl-g-g' if your terminal is ADN connected and if `EXT' does not work after several tries, try `IPL CMS' as below.}
EXT (CR) {External interrupt of the CP control program, rather than a CMS interrupt, can be used following an `(Esc),' discussed above.}
HX (CR) {Halt execution of CP, rather CMS, reactivates your CMS session after an `EXT' with IBMNET still active without using `GETDISK'; you need only use `telnet mario.psc.edu' to return to your UNICOS session.}
HT (CR) {Halt typing in CP.}
Ctrl-g-g {The UIC ADN escape of last resort. If this does not work, your terminal is not connected to ADN because it is directly connected to CMS or probably has an improper escape command defined, so you should try `EXT (CR)' and if that does not work, call a UIC consultant. Follow this UIC ADN escape by the following `DONE', `CALL' and `IPL CMS' to return to CMS as given below:}
``#'' DONE (CR) (CR) {This ADN command is used with the `last resort' `Ctrl-g-g' interrupt to kill the CMS session along with TELNET, so you have to get back on CMS and TELNET to kill or re-connect to your VMS or UNICOS session. ``#'' is the ADN prompt. To re-connect to CMS, enter:}
``#'' CALL [N] (CR) {Here [N] is the number appropriate for your terminal if ADN connected (e.g., use `31' on a SEO hard-wired terminal or `1200', else `2400', on a dial-up terminal.). Enter your terminal type, login data and if get the message like ``RECONNECTED...'' with ``CP READ'' at the bottom of the screen, enter:}
BEGIN (CR) (CR) {Begin should restore your session to the state it was in just about before the abort, but it can sometimes, although not always, return you to a stuck session if you escaped from one. If still stuck try to abort the session again and use the command:}
IPL CMS (CR) {Proceed as usual, but if you don't get a message like that skip the above step and proceed as usual. stuck session if you escaped from one. `GETDISK TELNET' and `TELNET borg' or `TELNET MARIO.PSC.EDU' again. When TELNET asks if you want to re-connect type `yes (CR)', so that you can clean up your UNICOS or other remote session. The `(Esc),' method gets you back to the CP control program that CMS is embedded in, instead of Ctrl-g:}
(Esc) . {This `PA2' interrupt, on most terminals, behaves as a screen clear in UNICOS.}
(Esc) {This `PA3' interrupt, on most terminals, behaves as a command buffer emptier like the `PF6' key in CMS. Use it to repeat a prior command by pressing it until the desired prior command is displayed and press return `(CR)' to re-execute it in UNICOS.}
Ctrl-g (SPACE) {Kills keyboard lock; this works similarly in UNICOS with IBMNET.}
Ctrl-r-g {Kills stuck session.}
Ctrl-q {Kills stuck cursor, not at lower left.}
(Clear-key) {Response to ``more'' for more text; also clears un-entered input. When CMS is accessed through a
tn3270
IBM3270 emulation telnet command (emulation assumed in CMS), then the `Clear-key' is the
Ctrl-z
key combination.}
The default control character is `\' for IBM Telnet. Enter `?' or `help' after the IBM Telnet ``Command:'' prompt for more functions, such as commands for changing the defaults.
PF4-key {Interrupt PSC process and return to TELNET with the ``Telnet command:''; respond with `quit' to abort the IBM Telnet session or use a pure `(CR)' to return to the remote session or `?' for help; PF-5 to PF-15 also work.}
(CR) {Re-connect to PSC session from TELNET, depending on what intervened after aborting a session; also use if you pressed the `PF4-key by mistake or get the ``Telnet command:'' prompt when you do not want it.}
\d(CR) {Restart(?) login to PSC if you made an error in `Username' or `Password' and receive a message like ``User Authorization Failure''; but note placed here for convenience since you need to know it before the PSC prompt.}
See also the Local Guide Section UNIX Control-Key Commands.
Ctrl-h : Erase or backspace over character; note the CTRL-key and h-key must be simultaneously pressed.
Ctrl-c : Interrupt or break character; stops printing and returns to UNICOS. {Caution: for a IBM TELNET session, should use \c (CR), but this masked interrupt will not work during long listings due to interference of the CMS `Clear-key' in IBM Telnet sessions.}
Ctrl-s : Stop character {else or IBM Telnet use ` \s (CR)'}.
Ctrl-q : Quiet character {else for IBM Telnet use `\q (CR)'}.
Ctrl-u : Kill character {else for IBM Telnet use `\u (CR)'}.
Ctrl-w : Word erase character {else for IBM Telnet use `\w (CR)'}.
Email Comments or Questions to hanson@uic.edu