Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!rutgers!att!chinet!patrick
From: patrick@chinet.chi.il.us (Patrick A. Townson)
Newsgroups: comp.sys.apple
Subject: Re: Chr$(4) and Linefeeds
Message-ID: <7560@chinet.chi.il.us>
Date: 28 Jan 89 14:58:57 GMT
References: <8901270945.aa15170@SMOKE.BRL.MIL>
Reply-To: patrick@chinet.chi.il.us (Patrick A. Townson)
Organization: Chinet - Public Access Unix
Lines: 28

In article <8901270945.aa15170@SMOKE.BRL.MIL> UNCKNG@UNC.BITNET ("Kevin N. Gunn") writes:
>  I've come across this problem before (and fixed it by issuing a
>print chr$(4) twice, the first of which is, of course, terminated by
>a carraige return, thus solving the problem).  What I'd like to know
>is WHY DOS 3.3 NEEDS that carraige return.
>
>Carraige return sure is a strange anachronism when applied to a
>video screen, isn't it?

It isn't that it needs a LF or CR, but rather, a DOS command <must> be the
first command on a multi-command line. A CR insures that the command
which follows immediatly is the first command on a line.

It is common in Applesoft to print something, and terminate the print
statement with a semi-colon, which then will suspend the CR/LF and force
the next print statement to begin right at the end of the first one.
Depending on the complexity of the code, somewhere along the line you may
have left a print statement unclosed in this fashion. If so, and you hit
a line of code with a DOS command, then that command will not execute
correctly. Setting up D$ = CHR$(13);CHR$(4) right from the beginning of
your program insures a new line will be started when you need one in
this context.


-- 
Patrick Townson 
  patrick@chinet.chi.il.us / US Mail: 60690-1570 (personal zip code)
  FIDO: 115/743 / AT&T Mail: 529-6378 (!ptownson) /  MCI Mail: 222-4956