Newsgroups: comp.protocols.kermit.misc Date: Mon Apr 24 10:24:29 1995 From: Frank da Cruz <fdc@columbia.edu> Subject: Re: arrow keys and www? Organization: Columbia University 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). >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 key has a "verb" assigned to it:
Up arrow \Kuparr Down arrow \Kdnarr Right arrow \Krtarr Left arrow \KlfarrThese 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 Dwhere 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:
[NOTE: In Kermit 95, the arrow keys, along with all other keys, are set up automatically whenever you give a SET TERMINAL TYPE command.]
- Frank