Stunt Car Racer Performance patcher

Version 1.6.3. This release is primarily intended for emulation. It provides 50 Hz physics and rendering at up to 50 FPS, while lap timers retain their original 8.33 Hz update rate, and detects PAL or NTSC displays at boot. The achieved frame rate depends on the machine's Chip RAM access speed; game speed stays correct when frames are late. The patcher also writes a WHDLoad install of the same game for a hard disk.

• Python 3.8+; no additional packages or assembler needed to patch a disk.
• Primarily an emulated Amiga with PAL or NTSC, MC68060, 2 MiB Chip RAM and at least 1 MiB Fast RAM (requirements). Lower frame rates may call for adjusting Game Speed in Settings.
• Your own original Stunt Car Racer ADF matching the supported checksum, and your own Kickstart ROM.

python3 patch.py "/path/to/Stunt Car Racer.adf"

Creates StuntCarRacer-Performance-v<version>.adf beside the original. Use --output /path/to/output.adf to choose a location and --force to replace an existing output. The original disk is never overwritten. python3 patch.py --version prints the package version.

Boot the patched disk in DF0.

python3 patch.py "/path/to/Stunt Car Racer.adf" --whdload

Creates the new install directory StuntCarRacerPerf and its drawer icon StuntCarRacerPerf.info beside the original; --whdload DIRECTORY chooses another place. Copy both to the Amiga and start the game from its icon, StuntCarRacerPerf. The intro is skipped, the loading picture stays for 3 seconds (or with WHDLoad's ButtonWait option until a button is pressed), and custom tracks, records and season saves are files in the install directory. The install's own file names let it share a directory with other WHDLoad installs of the game. Requires WHDLoad 17 or later and at least 2 MiB Fast RAM; see WHDLoad install.

Build in the game's 3D view, with a 16 × 16 ground grid, up to 64 internal pieces and 33 section choices. V toggles an overview of the whole track and building area.

• Left/Right (joystick or cursor keys): browse pieces or compatible choices.
• Fire/Space: preview, edit or confirm the selected section. After appending to an open track, the next press starts another addition.
• Q/W: turn the view in 45-degree steps. A/Z: zoom in and out. Straight hills, ramps and crests are previewed from the side.
• Esc: cancel a preview or leave the editor. Unsaved changes offer Save, Discard or Cancel.
• Backspace: remove the selected section. U: undo the latest edit.
• N: start a new track after confirmation.
• S / L: save or load a named track.

While choosing, the bottom lines show the section's name, its rise, the choice number and, for a red section, why it does not fit. On an open track the last line shows where the start line is from the open end, for example START 3 RIGHT 3 FWD UP 2 FACE R90: map squares to the side and ahead, height levels, and the start line's direction. A section that closes the track is marked.

The game disk has 32 save slots on two pages. Slot 01 contains the ready-to-drive example track BUILD; saving over it replaces it after confirmation. Draft tracks can be saved and resumed; only validated Ready tracks appear in Practise. The original eight tracks remain available. Custom tracks retain their own best times, separately for normal and super league. Record eligibility requires Game Speed at 100%, Infinite Boost No and Disable Damage No.

Save/Load → Disk exports or imports tracks using DF1. Enable a second floppy drive and insert a writable ADF for track storage. Initializing that disk erases its contents after confirmation. It provides another 32 slots; records are not exported to DF1. DF0 stays the game disk. Under WHDLoad, tracks are files that can be copied instead.

Keep the patched game disk writable to retain tracks and records. Back it up before replacing it with a newly patched image; patching the original creates a fresh disk and does not transfer saved tracks. Export tracks to DF1 first and import them into the new game disk through the editor.

Two machines race each other over their serial ports (null-modem link). Both must run this version in PAL.

1. Choose Computer Link in the main menu on both machines.
2. Press H on one machine (Host) and J on the other (Join). Esc returns to the menu.

The Host's menu choices, including Settings, apply to both machines. Each machine runs its own 50 Hz physics; car positions are exchanged 20 times per second and the other car is shown smoothly with a short delay. Cars pass through each other. Pause, leaving the race, wrecks, results and points are shared. A tie is awarded to the Host. Link races do not change the records on either disk.

The link championship runs four seasons through Divisions 4, 3, 2 and 1, the last one being the FINAL SEASON. Points accumulate over all four seasons and the driver with the most points after Division 1 wins. Each new link championship starts in Division 4.

Settings in the main menu.

• Game Speed: 100–150%, in 5% steps.
• AI Difficulty: 100–150%, in 5% steps.
• Infinite Boost: No/Yes.
• Disable Damage: No/Yes,

Changelog · Checksums · Patch details · WHDLoad install · Assembly sources

Timo Heimonen (timo.heimonen@proton.me) · MIT License

The license covers the patch code and documentation. Original game disks and Kickstart ROMs are not included.