I routinely read in 3+ megabyte files.  That error in NCURRENT-POSITION
usually stems from one of two problems (I can't remember which right now)

a) String > 32K
b) Window displaying more than 32K lines (chars?) (other than toploop, which 
   handles    this)

If you're reading in big strings, perhaps READ-LINE(?), (a) may be the problem.
If you're displaying the file contents in some window, (b) may be the problem.

Sorry, I can't remember which one causes this, but I do hit it all the time.
I'd be a happy camper if Franz would fix both problems.  

> Date:          Tue, 10 Jun 1997 14:26:34 -0400 (EDT)
> From:          Julie Goldberg <cornell.edu at jbg7>
> To:            mailing list Allergo <cs.berkeley.EDU at Allegro-Cl>
> Cc:            Sam Lee <junglee.com at wklee>
> Subject:       reading in large files

> 	I'm using an application a friend wrote in ACL and trying to fix
> some bugs.  It works fine when it is asked to read in relatively small
> files.  When I ask the program to read in a file that is over 30K or so,
> it stops reading the file midword, midline.  When I try reading something
> over 100K or so, I get a stack overflow and ACL crashes.  This is when I
> run the program using ACL 3.0.0. 
> 	The program won't run under 3.0.1, but it does run using ACL
> 3.0.2.  In that version, it never stops reading midline nor does it give
> me a stack overflow.  However, it does not work completely.  It works
> successfully with larger files than 3.0.0 works; however, but somewhere
> between 30K and 38K files, it starts giving me an error and it stops
> reading the file when partway through.  It says:
> 
> Error: A numberic or character function was given an argument 110648 of
> the wrong type in NCURRENT-POSITION.
> 
> NCURRENT-POSITION is not a function he wrote nor is it a function he ever
> calls anywhere in his code.  When I try to look at the stack, all the
> calls being made are to printer functions or they are closures without
> names.  Does anyone know what NCURRENT-POSITION is?  Where it is called?
> What could cause such an error?  Thanks.
> 
> Julie
> 
> ------
> http://www.csuglab.cornell.edu/home/jgoldber/
> 
> 
>