Stunt Car Racer / Stunt Track Racer (Framerate Unleashed)

A modification of the 1989 Amiga game Stunt Car Racer (Geoff Crammond / MicroStyle) that unlocks the framerate to 50/60 FPS without changing the original speed or physics. Intended for Amigas with a fast CPU and fast memory — it will not improve performance on a stock Amiga 500.

PAL version — Stunt Car Racer

The modification is distributed as a WHDLoad slave. The installer (Install) can create a full installation from the original PAL floppy disk or the Quartex cracked ADF image, or upgrade an existing Stunt Car Racer WHDLoad installation by replacing StuntCarRacer.slave in place. Unrecognised disk images produce a clean WHDLoad error instead of crashing.

The tooltype C2=1 enables The New Tracks option, which plays the game using the track layouts from the TNT hack by AmiGer/CARE. Save and lap time data for the TNT tracks are stored separately in StuntCarRacerTNT.save and StuntCarRacerTNT.times.

NTSC version — Stunt Track Racer

A separate NTSC build (StuntTrackRacer.slave) targets 60 FPS on NTSC hardware. It requires a Stunt Car Racer WHDLoad installation using the original PAL disk — the slave loads and patches the PAL binary at runtime, replacing the title logo with the North American Stunt Track Racer branding.

The C2=1 tooltype works the same way as in the PAL version.

Known limitations

• Computer link play via serial cable is not supported.
• The original code has not been optimized in any way — there is probably room for improvement.

Files

• StuntCarRacer.s — Source code for the game with enhancements (PAL and NTSC, selected at build time with -dNTSC=1).
• StuntCarRacerSlave.s — WHDLoad slave for loading and running the game (StuntCarRacer.slave for PAL, StuntTrackRacer.slave for NTSC).
• Install — Amiga Installer script for creating or upgrading a WHDLoad installation.
• ReadMe — Readme distributed in the release archive, in WHDLoad template format.
• create_release.sh — Builds the release archive (StuntCarRacerUnleashed.tar). Run via make dist.

About the source

The code was initially disassembled from the game binary using ReSource. Labels have been renamed manually as the code was analysed. Modifications to the original behaviour are marked with comments such as ; added, ; removed, ; originally and ; fixed.

Credits

Written by Vesuri / dA JoRMaS — vesuri@jormas.com.

The WHDLoad slave is partially based on the work by Codetapper/Action! & StingRay.

Original game (1989): Geoff Crammond / MicroStyle.