Flash Gordon (Bally 1981)¶

An active VPW Premium toolkit build led by mcarter78, notable for advancing VLM segment display baking for VR backglass, flipper rubber color swap techniques, and documenting the PulseTimer requirement for Bally 6803 ROMs. Supported by apophis79, sixtoe, cyberpez, tomate80, metated, niwak, and flupper1.

Build Story¶

An ongoing Premium toolkit build for this classic Bally title. The project benefits from mcarter78's systematic approach and metated's VLM segment display technique originally developed on Warlok.

Table-Specific Details¶

Mechanisms & Hardware¶

PulseTimer requirement: A missing PulseTimer in the VPX table script prevents the Bally 6803 ROM from accepting coin credits, making the game unplayable. Symptoms: game enters attract mode but won't accept coins; drop targets don't initialize on plunge. The PulseTimer is required for proper ROM communication on this platform.

Art & Visuals¶

VLM segment display baking: Metated developed a technique to bake segment displays (score displays) directly into the VR backglass via VLM, eliminating separate score display rendering in VR. The segment display geometry is modeled in Blender and integrated into the backglass scene. The Blender file includes the setup and methodology for mapping ROM-driven display values.
Flipper rubber color options: Split rubber mesh from bat in Blender and set to white material. At runtime, an F12 menu option swaps the rubber material. Critical: swapped materials must be added to the room brightness array for correct lighting response. Limitation: strong lightmaps baked near flippers can overpower the material swap, making color changes invisible when lit.
3D bake target inserts: Bake target objects in Blender create more realistic inserts than flat flasher approaches. The bottom face of the bake target must be removed to prevent unwanted lightmap application, and the playfield mask must sit below the playfield surface.
Bumper decal nestmap workaround: When toolkit-baked nestmaps produce artifacts on small metallic objects like bumper cap decals, removing the nestmap and applying a standard VPX metallic material instead produces a cleaner result.

ROM Variants¶

Flash Gordon has multiple ROM variants with different hardware: - flashgdv.zip -- Early production using Vocalizer and Sounds Plus modules, supported a high-voltage backbox strobe - Parent ROM -- Production code after operators complained about the strobe; speech moved to Squawk & Talk board - Prototype ROMs (flashgdp.zip, flashgp2.zip) -- Used the 68701 CPU with expanded capabilities: 9-segment alphanumeric displays, 64-switch matrix, 120 lamps, 26 solenoids. This prototype hardware was shelved in 1981 and didn't resurface until the 6803 series in 1985.

Known Issues¶

Fast GI approximation artifacts: Enabling fast GI approximation in Blender render settings causes lighting artifacts on plastics during toolkit bakes. The approximation speeds up rendering but produces inaccurate light transport for transparent materials. Fix: disable fast GI approximation for toolkit bakes.
Refraction probes for stacked plastics: Each overlapping transparent layer needs its own probe number; a single probe causes one layer to disappear entirely.

Techniques Developed Here¶

VLM segment display baking for VR backglass score displays
Flipper rubber color swap via F12 menu with material array integration