Under the microscope: Micro Maniacs Racing (PlayStation)
Also "Extending the demo"
In this edition, we’re examining Micro Maniacs Racing. The backstory for this game is described in the manual by way of a journal entry from the character Dr. Minimizer:
The world as we know it is on the verge of crisis – oil and food shortages abound. Economic chaos looms over the horizon, bringing with it war.
However, I have a vision, a vision to save humanity from certain collapse. I will minimize the people of earth to 1/360th of their original size thus creating a world of plenty for all.
I don’t see any problems with this plan, do you?
I found two things worth checking out in this game:
The retail version has a cheat code that somehow managed to stay hidden for the last 25 years.
There’s a demo version that was built two months before the retail version. It normally limits what you can access, but I made a patch that removes its restrictions.
Details are below!
The missing cheat code
Cheat sites have several codes listed for this game:
They’re missing one, however. Go to Options > Secret Options, hold down Select and enter Up, Down, Left, Down, Right, Down, X, Down.
If you got it right, a new Unlock All Characters item will appear:
When set to On, it makes the last column of characters available in the various race modes:
Technical details: When you’re in the game’s menu, the function at 8002c634 (in the PAL version) is checking once per frame to see whether you’re holding the Select button.
If you are, it starts looking through an array of eight pointers. Each one is for an array of 16-bit values that represent the game’s cheat sequences.
For the code above, the values look like this in memory:
800656e8 11 00 # Up
800656ea 41 00 # Down
800656ec 81 00 # Left
800656ee 41 00 # Down
800656f0 21 00 # Right
800656f2 41 00 # Down
800656f4 01 40 # X
800656f6 41 00 # DownThe prototype demo
The Codemasters Demo Disk, released in PAL regions some time in early 2000, has a playable preview of Micro Maniacs that describes it as “75% complete:”
The preview normally limits which items you can select on the main menu – only Challenge mode, Vs mode, and the Options screen are accessible:
However, the disc has data for the whole frontend. Each menu item’s availability is controlled by a value in the data structure at 801194b8. Items at indexes 3, 5, 7, and 8 are disabled by the initialization function at 8008baf0. Here’s Ghidra’s decompilation of the relevant code (with my variable names and comments added):
/* Disable "Time Trial" */
item_offset = retrieve_item_80067d9c(menu_data_loc_8009425c,3);
menu_data_loc_8009425c[item_offset * 0x20 + 0x5c] = 0;
/* Disable "Vs Teams" */
item_offset = retrieve_item_80067d9c(menu_data_loc_8009425c,5);
menu_data_loc_8009425c[item_offset * 0x20 + 0x5c] = 0;
/* Disable "Memoirs" */
item_offset = retrieve_item_80067d9c(menu_data_loc_8009425c,7);
menu_data_loc_8009425c[item_offset * 0x20 + 0x5c] = 0;
/* Disable "Memory Card" */
item_offset = retrieve_item_80067d9c(menu_data_loc_8009425c,8);
menu_data_loc_8009425c[item_offset * 0x20 + 0x5c] = 0;Replacing the zero assignments with nop commands makes all menu items available again.
Memoirs mode seems to have been disabled for the demo because it wasn’t finished yet. The first screen, which has Dr. Minimizer’s journal entry in the final version, is blank:
The character profiles on subsequent pages are also missing. There are some stats filled in, but they’re different from the ones shown in the final game. Also, the character V4 has a different name:
Pressing Select normally takes you out of Micro Maniacs and back to the Codemasters demo menu. This prevents you from entering cheat codes on the Secret Options screen, as they require you to hold the Select button. Changing this instruction disables that behavior:
8004dab0 nop # Don't jump to the Select button listenerThis version of the game is looking for two codes:
Unlock all characters: (Holding Select) Up, Down, Left, Down, Right, Down, X, Down.
Unlock all tracks (Holding Select) Triangle, Circle, Circle, Triangle, Down, Up, Up, Down.
They don’t have associated codes, but there are hidden menu elements for two secrets that don’t appear in the final game: Unlock V3 Tracks and Auto Power Mode. They don’t do anything when enabled, however.
V3 Tracks presumably refer to the tracks from Codemasters’ game Micro Machines V3!
The demo normally limits your choices on the character select screen, but enabling the Unlock All Characters secret above makes all of them accessible. This screen looks pretty close to complete, but Beatbox and Dynamo are in different positions:
The demo normally lets you pick one of two tracks on the track select screen. However, it has data for a third track. Changing these instructions prevents the third one from being disabled:
80090210 nop # Fall through to the code that enables "Hothouse Dash"
80090224 nop # Fall through to the code that enables "Party Poopers"Enabling every track shows that the demo has several with names that don’t match the final:
Others have the same name but a different icon:
The interface for Vs Teams mode seems to have been overhauled in between the demo build and the retail release:
There are many other differences in this build! Leave a comment if you find something interesting that I didn’t highlight.
Outro
You can get the patch that modifies the Codemasters Demo Disk from GitHub.
For many more articles on finding long-unknown cheat codes, see my New codes for old games section. And for additional information on modifying demo discs with prerelease builds, see the Extending the demo page.
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