After spending a good 30 minutes messing around with DOSBox, I found out how to activate cheats.
1. Go to the directory where you installed Fragile Allegiance. For me, it was in C:\Program Files (x86)\GOG.com\Fragile Allegiance, but it might be somewhere different for you.
2. Find the file called "dosboxFR.conf" and open it with Notepad.
3. Scroll down to the chunk of lines with [autoexec] at the top.
4. On the line that says FRAGILE.EXE, add /cKim.Jon.fmsti after it. It should look like this:
# Lines in this section will be run at startup.
mount C .
imgmount d "FRAGILE.DAT" -t iso
5. Save the file. (This may be a bit tricky since, at least for me, Windows refused to let me overwrite dosboxFR.conf. Instead it tried saving it in Documents as a .txt file. You can just save it somewhere else, replace the .txt extension with .conf(so it's dosboxFR.conf again) and copy it back into the folder to get around that, though.)
After that, all cheats should be enabled.
Note that each letter is a different cheat. You can remove certain cheats by removing the letter. Here's what each letter means:
f= build everything in one day
m= extra money
s= see all asteroids
t= change game speed. alt f7 slows time and alt f8 speeds up time
i= have all information about aliens and trading items.
(You will need to start a new game afterwards in order to use the cheats. Only the game speed cheat works in games started before activating cheats.)
Post edited April 20, 2014 by Murkat