Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cornell!uw-beaver!entropy!dataio!bright
From: bright@Data-IO.COM (Walter Bright)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Overlays
Message-ID: <2594@dataio.Data-IO.COM>
Date: 27 Jul 90 21:16:08 GMT
References: <1990Jul25.211808.29645@iex.uucp>
Organization: Data I/O Corporation; Redmond, WA
Lines: 20
Keywords: linker overlay

In article <1990Jul25.211808.29645@iex.uucp> bert@neptune.iex.com (Bert Campbell) writes:
<I'm using MSC 5.0 and the linker that is supplied with it (3.61)
<to create overlays in a big large-model program.  At first I couldn't
<get them to work at all, but we finally figured out that functions in overlays
<called via a function pointer wouldn't work with this linker.  Along with
<that are other limitations that make a better linker a requirement.

Zortech's VCM linker doesn't have this problem.

<I'm looking for general experiences with other linkers for creating
<large "heavily overlayed" programs.  Recommendations for a particular
<linker (RTLink? PLink?) with accompanying reasons would be a help.

Check out Zortech's VCM linker. It enables overlays to work much like
virtual memory, i.e. overlays are loaded on demand and placed anywhere
in memory where there happens to be room. Overlays are removed from
memory when malloc starts running out. There's an article explaining
the mechanics of it in the July C User's Journal.

P.S. I wrote it.