Path: utzoo!utgpu!water!watmath!clyde!rutgers!ucla-cs!zen!ucbvax!wnre.aecl.CDN!delaney
From: delaney@wnre.aecl.CDN (Grant Delaney)
Newsgroups: comp.sys.apple
Subject: Re: Vt100
Message-ID: <1002*delaney@wnre.aecl.cdn>
Date: 10 Jan 88 14:32:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 26

The differance between the the Vt100 and the VT52 is not just the length of
the sequence that Larry Virden mentions below.  The differances go much deeper
into how the screen locations etc are handled internally.

>The VT52 is MUCH easier to emulate than a VT100 since the pgm only has to
>scan for the single control character.  The ANSI escape sequences sometimes
>can be dozens of characters long!  If you have line noise, it can cause
>problems in that a sequence is misinterpreted.

This response I recieved from Don Elton when discussing his Shareware Program
TIC (Another entry in the list of terminal programs supporting VT52 and 
terminal emulations) better discribes the differance between VT52 and VT100.

>>  Look at the way GOTOXY sequences are handled by say a VT-52
>>compared to a VT-100.  With the VT-52 there's a PREFIX character, an ADDRESS
>>CURSOR character, followed by a single byte for the X coordinate and a single
>>byte for the Y coordinate (probably with some sort of offset).  On the VT-100
,
>>instead of sending a binary value for the coordinates, it sends an ascii
>>string.  i.e. to say column 64 a binary coded terminal might send the value
>>$40 while an ascii coded terminal would send the string "64" or $36, $34.
>>The ascii method wastes more time (is slower) and is harder to parse since yo
u
>>can't just use a table to do it.

Grant