Under the microscope: Ford Mustang: The Legend Lives & Ford vs. Chevy (PlayStation 2, Xbox)

Finding 20-year-old secrets in PS2 games with Ghidra and ring buffers

Last weekend’s edition was about hidden secrets in a Ford Racing game. In this edition, I’ll do more of that: this article covers Ford Mustang: The Legend Lives and Ford vs. Chevy for PlayStation 2 and Xbox.

Like many games from this era, these games shipped with cheat codes for unlocking special features. But these shortcuts don’t ever seem to have been recorded properly.

I decided to correct the record. Below are my notes on how I used runtime memory inspection, Ghidra, and a guess about rushed developers to find some long-hidden secrets.

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Ford Mustang: The Legend Lives

Ford Mustang: The Legend Lives was developed by Eutechnyx and released in April of 2005. It’s the fourth entry in the Ford Racing series, and features only Mustangs.

There are a bunch of unlockable cars, but as far as the cheat sites are concerned, you have to get them the hard way – by completing all of the game’s challenges. Can we find any shortcuts?

Answer: yes! I went looking and found that this game behaves a lot like Batman Begins. Here’s how I described its cheat code detection system:

Many games implement cheat codes like this: (1) When you press a button on the controller, record it in a buffer. (2) When the buffer reaches a certain length, check the buffer contents to see whether they match any special sequence.

On the Profile screen, pressing controller buttons fills the buffer that starts at memory address 00742e10.

The Profile screen

Based on the values that appear in the buffer when you press the D-pad, Up is 0x18; Down is 0x19; Left is 0x1a; and Right is 0x1b.

The memory buffer, filling up with values

Setting a read breakpoint for the buffer’s memory address reveals that the function at 00199960 is checking its contents every frame. It’s looking to see whether a pattern with 13 elements is present in the buffer. The 13 elements are:

0x18, 0x18, 0x18, 0x1a, 0x19, 0x18, 0x1b, 0x19, 0x19, 0x1a, 0x1b, 0x1b, 0x18

Those correspond to these buttons:

Up, Up, Up, Left, Down, Up, Right, Down, Down, Left, Right, Right, Up

If you enter them on the Profile screen, you’ll hear an engine revving sound effect. After that, all cars will be unlocked:

Left: A “Locked” car shown with a cover. Right: An unlocked car.

All of the track variants will also be available, including the reverse routes, the alternate routes, and the reverse alternate routes:

Left: The standard route. Right: The reverse alternate route.

Shortcut found! This works on both the PlayStation 2 and Xbox versions of the game.

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Ford vs. Chevy

Ford vs. Chevy came out in November of 2005. It was also made by Eutechnyx. Most of the cheat sites have this code listed for the PlayStation 2 version.

Complete challenges: At the title screen, press Circle, Circle, Circle, Circle, Square, Square, Square, X, X, X, Start, Select, Select, Start.

This does not actually work. What’s going on?

I started my investigation by searching for recycled code from Ford Mustang: The Legend Lives. Ford vs. Chevy came out only six months after that game, so I presumed that the developers reused certain elements.

The most cheat-relevant function in the older game is the buffer checking function described above. Ghidra’s disassembly of it starts out like this:

I searched for the bytes shown in Ford vs. Chevy and got an exact match in the function at 001dead8. Then I set an execution breakpoint for that function’s address.

I got a hit on the main menu screen – the one shown here:

The main menu screen

The reused function is checking for this input sequence:

Up, Down, Left, Right

Putting that in brings up an Enter Cheat screen:

I put a distinctive phrase into the text box and then searched for it in memory. Then I set a read breakpoint for its location. After pressing Enter, I got a hit on the function at 00342e50. This is an implementation of the standard C function strcmp:

The strcmp man page

The comparison target is:

00593988 "POINTS"

If that’s what you put in, you’ll have 625,000 points with which to buy cars:

Left: Buying Ford cars. Right: Buying Chevy cars.

This seems to be the only cheat phrase recognized. As above, it works on both PlayStation and Xbox.

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Outro

Although Ford vs. Chevy borrowed its cheat buffer checking code from Ford Mustang: The Legend Lives, it seems to share more with an earlier Eutechnyx game: Street Racing Syndicate. That game also uses the code Up, Down, Left, Right to summon a cheat entry screen. All of its cheat phrases seem to be known, however.

Logo by Ashlyn Anstee

Thanks for reading Rings of Saturn. If you liked this article, check out the archive for many more explorations in digital archaeology. I’ll be back with more articles soon. Subscribe to get the next one as soon as it’s published: