Help with farcoreleft() in Turbo C++

[RHYSLING MICHAEL S]

I'm writing a program that does a lot of textfile processing.  For
speed, I want to do most of it in RAM, allocating the biggest block
I can.  I am compiling in the compact model (64k code, 1Mb data) and
chkdsk says I have 300k free.  However, the following call to 
farcoreleft says I only have about 61k free.

unsigned long memfree;

memfree = (unsigned long) farcoreleft();
printf ("Bytes free: %lu\n");

Can anyone tell me what's going on?  Please email replies.

Thanks in advance,
Michael Rhysling
rhysling at spot.colorado.edu u