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A Jax arcade flyer.
|Designer(s)||Koji Hiroshita and team|
|Mode(s)||Single player, two-player co-op|
|CPU||Konami 052001, Z80, 63C09EP|
|Display||Raster, 224 x 288 pixels, 2048 colors|
A Jax (エー・ジャックス), eventually renamed A-Jax, is a vertically scrolling shoot 'em up arcade game released by Konami in December 1987. Similar to Contra and its "Gryzor", there was a European release of the game called Typhoon, which is the name used for Imagine Software's ZX Spectrum, Amstrad CPC, and Commodore 64 ports.
The players control a "Tom Tiger" helicopter (in the 2D stage) and later a "Jerry Mouse" fighter jet (in the 3D stage), and shoot enemies in the air and bomb them on the ground, collecting power-ups and defeating bosses to advance levels.
The game takes place in a fictional 2007 where the Earth has been conquered by alien invaders. The player combats the occupation forces using vehicles under operation code named 'A Jax' created to liberate the Earth. Game play is divided into two scrolling sections with two different vehicles: the first being a vertical scrolling section with the helicopter and a Rail scrolling stage with the jet/space fighter. The game spans eight stages and extends are set to 30,000 and a second at 150,000 points.
During the helicopter segments, the player has access to four different weapons including the Vulcan, Bomb, 3-Way, Triple and Laser. Each weapon is available through their own specific pick-up icon. However, the helicopter can only equip one firing weapon at a time with the Bomb being constant. The player also has access to Options which add additional firepower. The jet segments contrast highly from the helicopter segments in the complete lack of available power-ups and additional weapons beyond a machine gun and bomb.
The IBM PC and Tandy 1000 ports were done by Banana Development, Inc. (Programmer - Logan Poelman, Artwork - Chris Grow and Brenda Johnson, Music - Kris Krug) It was written completely in 8086 assembly language. A custom multitasking kernel was developed for the game, to provide for simultaneous animation, music, collision detection and scoring on the single tasking MS-DOS operating system, quite advanced for the time on the IBM PC platform. To support flicker free scrolling, double buffering was used. The music routines supported 4 note polyphony on suitable sound hardware, as well as sound effects related to the game play. (The computer graphics and the music for the game were authored/transcribed on an Amiga 500 and then the files transferred to the IBM platform used by the software designer.)