BallyAlley_r1_c1.gif BallyAlley_r1_c2.gif BallyAlley_r1_c4.gif
BallyAlley_r2_c1.gif BallyAlley_r2_c2.gif Arcade Games
(Based on the Astrocade Chipset)

Documentation relating to the arcade games that are based around the Astrocade chipset. These games include the following:

  1. Seawolf II (1978)
  2. Extra Bases (1980)
  3. Space Zap (1980)
  4. Wizard of Wor (1980)
  5. Gorf (1981)
  6. Robby Roto (1981)
  7. Demons and Dragons (1982; unreleased prototype)
  8. Professor Pacman (1983)
  9. 10 Pin Deluxe (1984; electro-mechanical)
  10. 10 Pin Champ / Strikes and Spares (1985)

For more information about these arcade games, see the following:

Arcade Games Based Around Astrocade Chipset

The Adventures of Robby Roto! - Parts and Operating Manual Adventures of Robby Roto!, The - Parts and Operating Manual
By Bally/Midway.
June 1982.

Table of Contents (Summary)

  1. Introduction
  2. Location and Setup
  3. Game Operation
  4. Maintenance and Repair
  5. Illustrated Parts Breakdown
  6. Technical Troubleshooting
  7. Coin Door Maintenance
  8. TV Monitor Manual
  9. Schematics and Wiring Diagrams

Reverse Engineering Robby Roto Adventures of Robby Roto!, The
Reverse Engineering Robby Roto: A 1980s Embedded System Masquerading as an Arcade Game
By Stephen Edwards, Columbia University.
January 2005.

Quoted from the paper's abstract:

"Robby Roto was an arcade game produced by Bally/Midway in 1981. Although not especially popular at the time, it does have the distinction of being one of the few commercial arcade games whose code is now in the public domain (the rights reverted to the author Jay [now Jamie] Fenton1, who released it in 1999). Although primitive by today's standards, it is representative of many early arcade games and illustrates a realistic, commercial embedded system.

"The description presented here has been synthesized from many sources, including disassembled ROM images; source code from MAME2, the multiple arcade machine emulator by Nicola Salmoria and many others; service manuals; and documentation on the Bally Astrocade home video game system3, which contains many of the same custom chips.

"Like many arcade games, Robby was one of a family built with similar hardware. Specifically, it shares its general design with Seawolf II (1978), Space Zap (1980), Extra Bases (1980),Wizard ofWor (1980), Gorf (1981), Professor Pac-Man (1983), and most interestingly, the Bally Astrocade home video game system (1978). All use the same microprocessor, a Zilog Z80, and the same custom graphics and sound chips, which were designed in part by Dave Nutting. For more history of these games and many others, see Herman [2] and Kent [3]."

Extra Bases - General Instructions Extra Bases - General Instructions
By Midway.

General instructions for Extra Bases. One sheet of paper describing in general terms: Installation, Line Voltage Safety Switch, Voltage Control Pots, Volume Control, Service Control Panel and Align Ball Control Sensors.

Extra Bases - Schematics Extra Bases - Schematics
By Midway.

Four schematics saved in TIFF format.

Extra Bases - Parts and Operating Manual Extra Bases - Parts and Operating Manual
By Midway.
July 1980.

Table of Contents:

  1. General Instructions - Upright
  2. General Instructions - Cocktail
  3. No. 761 - Extra Bases Upright - Front Picture
  4. Extra Bases - Rear Picture
  5. Ball Control Assembly
  6. Fluorescent Fixture Assembly
  7. Push Button Assembly
  8. Double Entry Coin Door Assembly
  9. No. 889 - Extra Bases Cocktail - Front Picture
  10. Extra Bases Cocktail-Interior Access Picture
  11. Ball Control Assembly
  12. Single Entry Coin Door Assembly
  13. Transformer Board Assembly
  14. Commercial Card Rack Assembly
  15. Power Supply Component Layout
  16. Power Supply Schematic
  17. Wiring Diagram - Upright
  18. Wiring Diagram - Cocktail
  19. Game Board Component Layout
  20. Game Board Schematic
  21. RAM Board Component Layout
  22. RAM Board Schematic
  23. CPU Component Layout
  24. CPU Schematic
  25. PC Boards parts list
  26. Wells-Gardner Monitor Schematic
  27. Wells-Gardner Replacement Parts List
  28. Wells-Gardner Monitor Schematic-Cocktail

Seawolf II Parts Catalog Seawolf II Parts Catalog
By Midway.

Table of Contents

  1. General Instructions
  2. Visual Adjustments
  3. Switch Adjustments (First 500 Games)
  4. Switch Adjustments (Post 500 Games)
  5. No. 625 - Sea Wolf II - Picture
  6. Periscope Mirror & Light Box Assembly
  7. Periscope Tube Assembly Front Door Assembly
  8. Transformer Board Assembly Additional Parts List
  9. Game Board Components Layout (D-Version)
  10. Game Board Components Layout (E-Version)
  11. Mother Board Components Layout (B-Version)
  12. Mother Board Components Layout (C-Version)
  13. Power Supply Components Layout
  14. Power Supply Schematic
  15. Monitor Schematic
  16. Characterization Card
  17. Wells Gardner Monitor Schematic
  18. Wells Gardner Parts List
  19. 25-Inch Color Monitor Schematic-Model G02
  20. Color Monitor Parts List

Seawolf II (Schematics) Seawolf II Schematics
By Midway.

This archive includes five schematics for the Seawolf II arcade game released in 1978.

  1. Seawolf II Comm Video Schematic (A084-90002-B625)
  2. Seawolf II Comm Video Schematic (A084-90002-C625)
  3. Seawolf II Game Logic Schematic (A084-90700-D625) (6-1-1978)
  4. Seawolf II Power Supply Schematic (A082-90401-B000)
  5. Seawolf II Wiring Diagram Schematic (6-1-1978)

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