Extending the demo: Dave Mirra Freestyle BMX (PlayStation)
Not featuring Slim Jim Guy (yet)
The September 2000 issue of Official U.S. PlayStation Magazine includes a preview of Dave Mirra Freestyle BMX. It’s marked as a Work In Progress, and doesn’t let you see much. You get to bike around for 90 seconds before a promo for the forthcoming release appears.
There’s more to see however, however. Normally when you press X on the first screen, the function at 80079cdc gets called with an argument 0x08.
That function switches menu screens. Change its argument to 0x09, and you get the Select Game screen. This lets you pick from seven different types of gameplay:
Best run
High five
Horse
Random spot
Wipeout
Longest grind
Highest walltap
An expanded version of this screen appears in 2 player mode in the final game. The demo build is missing Big Air Contest, Furthest Jump, and Longest Manual:
You can change the time limit for Best Run mode in the demo build – the options are 30 seconds, 60 seconds, 1 minute 30 seconds, and 5 minutes. The final game swaps 1 minute 30 seconds for 2 minutes.
The demo build has a Horse game, but the final game calls it B-M-X. The idea is the same in both versions, but the letters are different.
The classic basketball game, adapted for BMX. One player does a trick, and the other must match it, or get stuck with a letter.
There are a few other notable things in the demo build that you can see without a patch. One is the First Person camera mode:
This didn’t make it into the final game. It’s very disorienting; I can see why it got cut.
The other is the Color Adjust screen, which also doesn’t appear in the final game:
The demo build doesn’t seem to have any more menus. There are functions that refer to other menus, but they’re just stubs. Here’s Ghidra’s decompilation of one:
int init_menu_mode_8005d5d8(void)
{
debug_print_80080068("initializing menu mode (probably an error)\n");
return 0;
}There is a build date in the binary – this demo is from about three months before the final game:
800afb2c "May 18 2000"It also seems to be missing the screens that allow you to switch riders and stages.
Based on the game data, the main set of riders didn’t change between May and August. But the two bonus ones hadn’t been nailed down by the time the demo was built: instead of Slim Jim Guy and Amish Boy, the game data has TestA and TestBee:
800df070 "DAVE MIRRA"
800df088 "RYAN NYQUIST"
...
800df160 "TESTA"
800df178 "TESTBEE"Alas, there aren’t models for these stand-in characters – they are just copies of Dave Mirra.
Outro
You can get a patch that enables the Select Game menu in this demo from GitHub. It changes one byte – the instruction that sets the screen ID:
800732f0 li a0,0x8 # Before
800732f0 li a0,0x9 # AfterLeave a comment if you find something interesting that I missed!
For previous notes on reverse engineering Dave Mirra Freestyle BMX, see my article on its cheat codes. And for many more explorations of demo disc builds, see my Extending the demo series of articles.
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