Subj : DOS overlays
To   : borland.public.cpp.borlandcpp
From : Doug Nichols
Date : Tue Jun 08 2004 10:07 am

I am (still!) supporting a suite of DOS order-entry and invoicing 
programs I wrote in the early 1990s under BC++ 3.1.

The largest exe in the project is around 500K. As an overlay it leaves 
about 130K of RAM available at the point where it is fully initialised 
and waiting for a keystroke. It has been trouble-free for years. The 
same program compiled as a standard DOS exe (without overlays) has 30K 
of RAM available at the same point, and fails before it has a chance to 
be useful.

I am currently converting the whole project to BC++ 5.02 (a platform I 
have used a lot for Windows programming) and I now find that overlays 
aren't working. The programs behave the same regardless of my choice of 
Standard or Overlay - the same, in fact, as the non-overlaid ones built 
under BC++ 3.1.

I believe I have set all the appropriate options. The generated make 
file appears to be correct, including linking overlay.lib.

Is there something I am missing here?

Doug Nichols

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