This is ToxicFrog's High Resolution Patch as
discussed here on TTLG.
It adds the following resolutions to System Shock: 800x600, 1024x768 & 1280x1024.
The file you'll want to download is
ss1hr.exe.
Make sure your game executable (CDSHOCK.EXE) is not write protected.
Then in windows explorer drag
CDSHOCK.EXE onto
ss1hr.exe. Follow the onscreen advice.
Alternatively issue the following command in a DOS prompt:
ss1hr CDSHOCK.EXE
If you're using Mouse2KV, you'll have to edit the
cdshock.bat file to avoid issues with your mouse not being able to reach all corners of the screen. In
cdshock.bat change "640 480" to the resolution you're going to be using with the patch.
Play with the mouse acceleration until it's a good speed for you.
If you are an owner of a nVIDIA GeForce4 your monitor might give you an "out of range" message, or shut off. In this case please download
nVidiaGeForce4_winxpfix.exe, run it and reboot.
If you are running a pure DOS machine and cannot use the win32 binary (ss1hr.exe) there are prepatched versions of CDSHOCK.EXE available below. Backup your original and rename one of the prepatched executables to CDSHOCK.EXE.
The file
ss1hr.c is the source code for the patch.
Thanks to TheNightTerror and ToxicFrog for help with writing this summary.