home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
kermit.columbia.edu
/
kermit.columbia.edu.tar
/
kermit.columbia.edu
/
newsgroups
/
misc.19950329-19950528
/
000216_news@columbia.edu_Mon Apr 24 14:22:39 1995.msg
< prev
next >
Wrap
Internet Message Format
|
1995-07-31
|
4KB
Received: from apakabar.cc.columbia.edu by watsun.cc.columbia.edu with SMTP id AA29387
(5.65c+CU/IDA-1.4.4/HLK for <kermit.misc@watsun.cc.columbia.edu>); Mon, 24 Apr 1995 10:22:46 -0400
Received: by apakabar.cc.columbia.edu id AA14964
(5.65c+CU/IDA-1.4.4/HLK for kermit.misc@watsun); Mon, 24 Apr 1995 10:22:43 -0400
Path: news.columbia.edu!watsun.cc.columbia.edu!fdc
From: fdc@watsun.cc.columbia.edu (Frank da Cruz)
Newsgroups: comp.protocols.kermit.misc
Subject: Re: arrow keys and www?
Date: 24 Apr 1995 14:22:39 GMT
Organization: Columbia University
Lines: 77
Message-Id: <3ngc7f$ejh@apakabar.cc.columbia.edu>
References: <3n2s56$rb4@news-2.csn.net>
Nntp-Posting-Host: watsun.cc.columbia.edu
Apparently-To: kermit.misc@watsun.cc.columbia.edu
In article <3n2s56$rb4@news-2.csn.net>, Gideon Weisz <gweisz@csn.net> wrote:
> this has to be a VEry simple problem, so apologies in advance, but i am
> stuck. in www, using lynx, with mskermit 3.14 and vt220 (and hebrew
> macro) the arrow keys do not work right. to move among highlighted
> links, one is supposed to use the up/down arrows and to move among
> levels the left/right keys. however, if i use right-arrow, i get "do
> you wish to send a comment" if i use left-arrow it is taken as a command
> to download down-arrow moves me up! (up the screen to the last
> highlight) how can i get out of this cleftstick?
>
Kermit is emulating a real VT220 terminal.
The VT220 cursor (arrow) keypad can be in one of two modes: cursor mode and
application mode. These keys send different escape sequences depending on
which mode they are in. When a VT220 is turned on (and when Kermit is
started), the arrow keys are in cursor mode.
By default (that is, unless you give SET KEY commands to change things),
MS-DOS Kermit uses the IBM keyboard arrow keys as the VT220 arrow keys.
Each arrow key has a "verb" assigned to it:
Up arrow \Kuparr
Down arrow \Kdnarr
Right arrow \Krtarr
Left arrow \Klfarr
These verbs track the cursor keypad mode automatically, and send the
following escape sequences:
Cursor Mode Application Mode
\Kuparr CSI A SS3 A
\Kdnarr CSI B SS3 B
\Krtarr CSI C SS3 C
\Klfarr CSI D SS3 D
where CSI is ESC followed by left bracket ([) on a 7-bit connection or
decimal 155 on an 8-bit connection, and SS3 is ESC followed by O
(uppercase letter O) on a 7-bit connection and decimal 143 on an 8-bit
connection.
How does the cursor keypad mode change? The host can change it by
sending special escape sequences, or you can change it yourself by using
the command:
SET TERMINAL ARROW-KEYS { CURSOR, APPLICATION }
So why do the arrow keys not work in Lynx? Or, in general, in any
particular application:
1. Because the application expects the keypad to be in one mode when it
is in the other mode. This is a deficiency on the part of the
application. Applications should never ASSUME which mode the cursor
keypad is in, but rather, they should PUT the keypad in the desired
mode, or else they should accept arrow-key codes from either mode.
Workaround: tell Kermit to SET TERM ARROW CURSOR (or APPLICATION).
2. Because of a terminal-type mismatch. Lynx, in particular, does not
seem to use the standard termcap/terminfo database, and so therefore
might not understand Kermit's VT220 or VT320 terminal type. Solution:
tell Kermit to SET TERM TYPE VT100 and also tell the host your
terminal type is VT100, before starting Lynx.
3. Because of a character-size mismatch. If you have been using a
VMS-based VT220 or VT320 fullscreen application (such as ALEPH, EVE,
etc), you might find that your arrow keys are sending 8-bit codes
rather than 7-bit codes, and then when switching to another
application like Lynx, the new application might not understand the
8-bit codes. Again, this is a deficiency of the application.
Workaround: tell Kermit to SET TERM CONTROLS 7.
I put MS-DOS Kermit into Hebrew mode, accessed the ALEPH software, tried
the arrow keys and they worked OK. Then I left ALEPH and started Lynx and
got the same symptoms you reported. The three steps above fixed the
problem.
- Frank