Help me hack my 30 year old shareware game

Question

So I recently found the binaries for a shareware game I released almost 30 years ago. Unfortunately I don't have the source code so cannot generate the "key" to unlock all the levels of the game. I'd like to put the unlocked game up on the web.You can play the game here: http://play.rabidgremlin.com/gridlok/ (I'm pretty amazed you can play an old DOS game in a web browser) and download the game's files here: http://play.rabidgremlin.com/gridlok/gridlok.zipThe .zip file has GRIDREG.EXE which was used to create the unlock key. Also I guess it would also be possible to patch GRIDLOK.EXE so that it thinks it's registered.Figured it might be a fun challenge for someone out there!

ksaj · Accepted Answer

Depending on the actual chronology, you might be able to use an old version of f-prot to remove the PKLite container.
The first versions of f-prot's heuristic virus removal software considered PKLite's method of jumping around to replace the PKLite code with the original code entry point to be a viral behaviour, and happily decompressed the binary and stripped off the PK container straight off. Sometimes it left crud on the end, but that didn't harm anything.
Needless to say, both FRISK and PK updated their code to not trample or trigger each other.

sigmaprimus · Answer

Did you create this game? You said that you released it but that is different. If You did create it and just lost the source, what language and or IDE did You use to write it?