The commonly available prepatched version of Grand Prix 4 has an annoying problem of nagging for a CD despite being cracked if you don't have an optical drive in your PC. This tool modifies that version's GP4.exe to remove the said check so the game can be played without using the virtual drive-trick as described by the source where you get the game.
The tool accomplishes this by changing two code jumps to NOPs thus bypassing the check. It's functionality has been tested to the degree that the game launches without the virtual drive trick but no long testing has been done in terms of gameplay.
Download the release and place the file (GP4patcher.exe) in the same folder as your GP4.exe file and follow the instructions after you launch the patcher. You might want to take a copy of your GP4.exe just in case even though this program has been tested to work properly. The tool will only modify the version of GP4.exe that matches the hashes below. It also has a built-in hash check before it does anything so if you don't know to check the hash, you can just try it.
| Algo | Hash |
|---|---|
| MD5 | eb6d756ad1a17e8f8b6f77177507b550 |
| SHA1 | 592903176a7d52e0ad0deef2541a88554ed4181d |
You don't need this section just to use the tool.
Compiling has been tested on Windows. The release binary has been compiled as 32bit to increase compatibility with older hardware that you might be using to run this game. It's also been manually compressed using the highest level of UPX to reduce the filesize.
Compile for 32bit:
nim c -d:release --opt:size --cpu:i386 -t:-m32 -l:-m32 GP4patcher.nim
or for 64bit:
nim c -d:release --opt:size GP4patcher.nim