Path: utzoo!utgpu!watmath!att!cbnews!cbema!las
From: cbema!las@cbnews.ATT.COM (cbema!las)
Newsgroups: comp.emacs
Subject: Re: Setting the Mark in emacses
Message-ID: <8551@cbnews.ATT.COM>
Date: 24 Jul 89 16:38:06 GMT
References: <2308@bingvaxu.cc.binghamton.edu> <638@megatek.UUCP>
Reply-To: cbema!las@cbnews.ATT.COM (Larry A. Shurr)
Organization: AT&T Bell Laboratories, Columbus, OH (actually an AGS consultant)
Lines: 28

From article <2308@bingvaxu.cc.binghamton.edu>, by consp04@bingvaxu.cc.binghamton.edu (Daniel F. Boyd):
> When using GNU Emacs on our VAX 8530, with a VT220 terminal,
> I can quickly and easily set the mark with control-spacebar.
> The terminal likes to send a ^@ (which I think is actually
> ASCII 0; a NULL) when you hit control-space.
[Can't do same on PC]
> Am I crazy, or is there a conspiracy?  I want control-space!

Depends on how you define conspiracy.  Most people don't get the scan code
and the current shift state and interpret keycodes themselves, they let
the BIOS do it.  If you use INT 16 to read the keyboard, ctrl-space is
just space.  Ctrl-@ (or ctrl-2) returns a 0 code in AL and 3 in AH.  If
you use INT 21 to read the keyboard then once again, ctrl-space is just
space and ctrl-@ is 0 followed by 3 because DOS uses the zero code to 
indicate that the next keycode is an extended key - i.e., pressing 
function keys and other extended keys results in DOS returning a two 
code sequence, requiring two separate reads, which always begins with a 
zero code.

Depending on what the author of the program you are running did, you
may be able to get what you want by pressing ctrl-@.

Good luck, Larry
-- 
Signed: Larry A. Shurr (cbema!las@att.ATT.COM or att!cbema!las)
Clever signature, Wonderful wit, Outdo the others, Be a big hit! - Burma Shave
(With apologies to the real thing.  The above represents my views only.)
(Please note my mailing address.  Mail sent directly to cbnews doesn't make it.)