suppress Runtime error 200 about comcom64 HOT 5 CLOSED

https://github.com/dosemu2/dosemu2/files/12823084/CASINO.ZIP
Test-case.
Needs to introduce the r200fix
command to comcom32 by hooking
the RM exception 0.

from comcom64.

The problem is that due to unknown
packer, the direct patching is not possible.
So we need a comcom32-based solution.

from comcom64.

The problem is that due to unknown
packer, the direct patching is not possible.

I'm casually following along here. I don't really know much about packers, so I'm presuming that the packer's decompression routine must expand the payload into memory somehow, then jump to it. At that point do we have enough information for say a new dosdebug feature to write a new uncompressed .exe to disk?

from comcom64.

You need 2 passes, loading the
program at different addresses.
Then you compare these 2 dumps,
find relocations and write them
to an exe header.
The challenge here is to find a
proper entry point.
Unpackers usually look for the
long jumps, and use Nth long
jump (with N=3) as an indication
of an entry.
That said, if you want to write the
dosdebug-based unpacker - you
are more than welcome. But its
not an easy task.

from comcom64.

r200fix is now implemented.
You also need dosemu2 from git
as there were bugs with RM exceptions
handling. Good that we finally have
a test-case for that (probably the last
one) untested dpmi bit.

from comcom64.