[comp.os.msdos.programmer] Compressors and overlays

dmurdoch@watstat.waterloo.edu (Duncan Murdoch) (01/11/91)

In article <4383@mindlink.UUCP> a563@mindlink.UUCP (Dave Kirsch) writes:
>> kgowen@cie.uoregon.edu writes:
>> One last note, I would not recommend using one [LZEXE, PKLITE, etc] of these
>> compressors if your program uses overlays.
>
>Actually, you can use it if you are using Microsoft Link style overlays.  You
>can't compress the overlays, but you can compress the root EXE code.  

I've seen one program (Binkleyterm version 2.3) that's compiled with MSC and
has overlays included which won't run after PKLITE compresses it.  I don't
know which linker was used for it.  In just about every other case I've tried,
with the notable exception of protected mode programs, they've run fine after
compression.  In fact, there's no noticeable difference in load time, 
presumably because I've got such a slow disk.

> What's
>involved is after you link your application with MS link using overlays, you
>have to run a program to split the root code and the overlays into seperate
>files, then run something like LZEXE on the root code, then glue all the
>overlays back together.

With PKLITE, this isn't necessary:  it does the splitting and gluing for you.

Duncan Murdoch
dmurdoch@watstat.waterloo.edu