From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Lars Brinkhoff Newsgroups: gmane.emacs.devel Subject: Meaning behind Control-G Date: Mon, 01 Jun 2020 07:29:02 +0000 Organization: nocrew Message-ID: <7w367f6y81.fsf_-_@junk.nocrew.org> References: <70bb51fd-447d-928c-4d69-1c9673a44471@online.de> <871rnnvmdx.fsf@red-bean.com> <87pnb7sira.fsf@red-bean.com> <87lflcg0k9.fsf@red-bean.com> <0f1cd319-fa8c-4453-b909-fdd36f337906@default> <87zh9scdf8.fsf@warpmail.net> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="123698"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) To: emacs-devel@gnu.org Cancel-Lock: sha1:DF1AlYpgyavbh+trtQHKCKo12B4= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Jun 01 09:29:42 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jfetB-000W4B-N8 for ged-emacs-devel@m.gmane-mx.org; Mon, 01 Jun 2020 09:29:41 +0200 Original-Received: from localhost ([::1]:49704 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jfetA-0003oE-Ps for ged-emacs-devel@m.gmane-mx.org; Mon, 01 Jun 2020 03:29:40 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47424) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jfesh-0003Ow-Db for emacs-devel@gnu.org; Mon, 01 Jun 2020 03:29:11 -0400 Original-Received: from ciao.gmane.io ([159.69.161.202]:56950) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jfesg-0006W1-GA for emacs-devel@gnu.org; Mon, 01 Jun 2020 03:29:11 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1jfesd-000VQX-BB for emacs-devel@gnu.org; Mon, 01 Jun 2020 09:29:07 +0200 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=159.69.161.202; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/01 03:29:08 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:251716 Archived-At: > > > > What does C-g mean? Why the sequence C-g specifically? I think > > > > the disconnect may be that C-g appears outwardly meaningless. > > > I will ask Greenblatt -- he might remember. > > I suspect there is no deep meaning behind it, the BEL was common way > > back then to mean abort, or alert. TECO and DDT both used C-g for > > abort, > Are you confident of that? I don't remember, but if your memory is > clear, that is probably the reason. I remember it clearly, because I use ITS DDT almost daily. TECO, not so much but it's easy enough to verify. Now, why TECO uses Control-G for "quit", I don't know. ASCII "BEL" as an "alarm" is a plausible theory, but hard to verify. In general there's no strong link between control characteras as inputs and their corresponding output behaviour. I see no control character commands here, so maybe Control-G wasn't in use with PDP-1 TECO: http://www.bitsavers.org/pdf/mit/rle_pdp1/memos/Murphy_PDP-1_TECO.pdf I don't see Control-G Here either, so maybe it was added after 1964: https://github.com/larsbrinkhoff/its-archives/blob/master/ailab/pdp6-memo-2.pdf