XCOM 2: Terror from the Deep, the sequel to XCOM: UFO Defence was released by MicroPose in 1995. The game came on either on several 3.5" floppy disks or a single CD and ran in DOS. Recently Firaxis released a remake and a sequel.
The original game was difficult even on the easiest difficulty settings and missions usually ended with the squad losing morale, either running off, firing wildly into the nearest friendly unit, or dropping a live grenade and subsequently exploding.
To even things out, we can edit the game's save files and improve our odds a bit.
The save files are stored in subdirectories labelled
GAME_10. If no game is saved the subdirectory will contain a single mostly empty file,
DUM.BIN 4.0K in size.
Once a game has been saved the subdirectory is populated with data files.
ACTS.DAT ASTORE.DAT CRAFT.DAT FACIL.DAT LEASE.DAT MISSIONS.DAT PURCHASE.DAT SITE.DAT UIGLOB.DAT XCOM.DATA KNOW.DAT BASE.DAT DIPLOM.DAT IGLOB.DAT LIGLOB.DAT PRODUCT.DAT RESEARCH.DAT SOLDIER.DAT UP.DAT ZONAL.DAT ALIEN.DAT BPROD.DAT DUM.BIN INTER.DAT LOC.DAT PROJECT.DAT SAVEINFO.DAT TRANSFER.DAT XBASES.DAT
Using dhex to look at the
SOLDIER.DAT file we can see that it stores information, unsurprisingly, about our squad.
Looking at the information in game, we can see that our soldier's
Time Units value is 54 (36 in hexadecimal), which correlates to byte 1A in the
SOLDIERS.DAT file for the first member of the squad.
To verify this we can edit the value and then reload the game and see the new value on the soldier's stats page. Changing the value at 1A from 36 to 37 shows up on the soldier's stats page after reloading the game where the
Time Units value is now 55.
BASE.DATcontains the information regarding the underwater bases. From our save we can see the name of the base at the beginning of the file followed by some values that save the layout of the base.
Here is a screen shot of the file in dhex and in game
Building a Living Quarters next to the top Sub Pen and saving the file we can see that the value in DB has changed from ff to 01. We can also see that the Sub Pen, which takes up 4 spaces uses a different value for each space, 10 - 13 with 10 representing the top left corner and 13 the bottom right.
The values roughly correspond to the order in the
Build Facilities menu.
After the 36 bytes for each of the squares in the grid, the values store the remaining building time information. Building a Living Quarters takes 16 days, which shows up in
FF as 10, which converted to decimal is 16.
Before editing file
After editing the file the Time to complete value is gone
Editing the file to add a new building will result in a build time of 255. This may be because no memory was assigned to store the build time variable, or it may just be in a non obvious location.
Manually comparing changes in the file is a time consuming processes. A python script to copy the files before and after a save and then compare the differences would help speed things up.