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From: info-mac@uw-beaver (info-mac)
Newsgroups: fa.info-mac
Subject: MacTerminal and Answerback message
Message-ID: <2171@uw-beaver>
Date: Fri, 9-Nov-84 19:55:58 EST
Article-I.D.: uw-beave.2171
Posted: Fri Nov  9 19:55:58 1984
Date-Received: Mon, 12-Nov-84 10:55:32 EST
Sender: yenbut@uw-beave
Organization: U of Washington Computer Science
Lines: 32

From: Richard Garland <OC.GARLAND%CU20B@COLUMBIA.ARPA>
There was a question on the response MACTerminal gives to a host's 
inquiry.  There is a confusion here. There are 2 kinds of questions
that can be asked of the terminal, and 2 responses.

    o	The "Answerback message" is a remnant from teletype days
	when systems would call up terminals (like news service
	terminals) and ask for an ID.  The system sends the ASCII
	"ENQ" (<CTRL>-E) to get this response.  On a VT100 you can
	put this message in while in set up mode.  It is generally
	not used by time sharing systems.  I usually put my Dept.
	name in, since a thief probably wouldn't know how to reset
	it (or invoke it).  I only see it when I type some garbage
	by mistake and by chance a ^E comes by and the terminal sends
	back the ol' answerback message.  It is also sent by a VT100
	in response to a "long break" (SHIFT-BREAK on the VT100).

    o	The "Device Attributes" or "What are you".  This identifies
	the configuration of the terminal.  For Old style (i.e. VT52)
	DEC terminals it was invoked by "<ESC>Z" to which a VT52 would
	respond "<ESC>/Z".  For a VT100 it is invoked by the ANSI DA
	(Device attributes) sequence "<ESC>[c" or "<ESC>[0c"" (the "0" is
	optional).  According to the VT100 User's Guide the terminaal
	responds with the sequence "<ESC>[?l;Psc"  Where "Ps" is a number
	between 0 and 7 giving what options are present (i.e. AVO, graphics
	etc.)  The sequence mentions in the question to this news group:
	"<ESC>[E;V" does not fit this pattern so either Macterminal
	has its own ideas of ANSI sequences or the questioner may
	have made a typo.

					Rg
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