Alien Arena

The Video Game PCB by Duncan Brown

Alien Arena screenshot

Emulated in MAME !


[ARCADE] Video Game PCB

Alien Arena © 1985 Duncan Brown.

Player 1 (Thor) and Player 2 (Zespar) are battling it out in the Alien Arena. The game is timed, with 2 minutes for every 25 cents inserted, regardless of your choice of 1-player or 2-player. More time can be purchased at any time before the timer reads ':00'.

In a 1-player game you are Thor, with controls on the right, and the computer plays Zespar, on the left. In a 2-player game each of you chooses a set of controls. When time runs out in either game, it reverts to a "play as long as you can keep alive and possibly winning extra lives" 1-player game. If it started as a 2-player game, whoever is winning when time runs out is the one who gets to battle the computer.

The basic theme of the game is "capture the flag (while protecting your own)". You can assemble offensive and defensive aids by picking up 'pieces' strewn about your half of the playfield. The pieces are color-coded, randomly created and distributed, and different objects require different numbers of pieces to assemble. Once you start assembling an object, you must finish assembling it (pick up enough pieces for it) and place it... or 'flush' the pieces you've picked up so far. Flush is mostly used for when you accidentally picked up the wrong color piece... or when you don't have the required pieces to assemble the rest of the object. A status bar shows what object is under construction, and how many more pieces are needed. Only one object can be assembled at a time. Once it is assembled, you must carry it to where you want to place or launch it and press the 'place' button.

There is a delay at the beginning of each round before the flags appear, and then a further delay before the midfield barrier comes down. Use this time to start assembling an offense or defense or both (this keeps the opponent from just starting each round by making a suicide dash for your flag). When the flags do appear, their placement is random, but within a small distance from the back wall of your half of the arena.

A round ends when an opposing flag is captured by a player, or when a player is destroyed by one of his opponent's offensive or defensive objects. There are all sorts of nuances to how the objects behave, how they score, etc.


Alien Arena the  Video Game PCB
Click to enlarge
(members only)
Main CPU : Motorola M6809 (@ 1 Mhz), OKI M6808 (@ 894.75 Khz)
Sound Chips : DAC

Screen orientation : Horizontal
Video resolution : 292 x 240 pixels
Screen refresh : 60.00 Hz
Palette colors : 16

Players : 2
Control : 8-way Joystick
Buttons : 2


Short history by Duncan Brown:
"By 1984, I had reverse-engineered the hardware used in Williams' games to the point where I had essentially created a 'programmer's guide' for it. Destiny called, I had to write a new game from scratch for this great hardware! My original intent was to end up with a conversion kit that was more user-friendly than most (remember this was back when conversions were just starting to come into existence, long before JAMMA, and most of them were a complete mess to install). A new marquee, new side stickers, new control panel, and 12 EPROMs, and away you go! No messy wiring, board modifications, etc. My production costs would be low, my sale price could be high."

"Well, that was the plan anyway... Over the course of a year, I wrote Alien Arena. It was written in 6809 assembly language using a cross-compiler on an Apple II+. Using custom-designed and handbuilt emulator hardware ('24' 2Kx8 static RAMs on a board connected to the Apple with a custom bus interface!) I could test out my code without the slowdown of programming and erasing a bunch of EPROMs all the time."

"When I was done, I assembled it into an ex-Stargate cabinet, and put it out in the arcade I owned at the time. I made a few modifications (mostly to the computer-player AI) based on feedback from customers. I cannot say it was an immense hit. Most people thought it sucked, frankly. You decide for yourself. I know my wife and I had a blast playing it while I was designing it (probably added 6 months to the time to finish it, heh heh heh...)."

This is quite literally the rarest game ever produced for the Williams hardware (production run of one!), and it has been out of circulation for 10 years.

Two blocks of copyright text are in the game. Unlike the rest of the text in the game, these messages are in ASCII format.
First message at 0x105E3:

Second message starts at 0x12596:


Designed by: Duncan Brown
From an idea by: Stowe Keller

Machine's picture.
Game's ROM.

Page last modified on July 22, 2014