Bally Astrocade

The Bally Astrocade was a second generation game console released by the video game Bally Division of the company Midway using a simple CPU that was only available on the retail market for a very small amount of time before the company retreated from the market. After Midway pulled out of the game market however the Astrocade was picked up by third party developers who re-released the system up until 1983. The Bally Astrocade is primarily recalled by gamers of the period due to it high powered graphics capabilities compared to similar console releases during that time.

History of the Astrocade:

The Astrocade was initially released by the Bally division under the name of the Bally Home Computer Library during 1977 and was only available for purchase through mail orders although due to massive setbacks during the production of the units none of the consoles would actually be shipped to consumers until 1978 at which point the console was renamed as the Bally Professional Arcade. The Professional Arcade was sold primarily through computer stores and received little exposure to the general public leading to infrequent sales which eventually led to Bally losing interest in continuing to focus on the arcade game market and the sale of its Consumer Products Division and its projects such as the development and production of the game console. Around this same point in time there was a group of third party developers who were working to design their own console the Astrovision which proved to be relatively unsuccessful. A corporate connection stemming from Montgomery Ward led to the connection between the developers and Bally which eventually led to a deal for the sale of the Consumer Products Division to the developers. After making the purchase the developers used Bally’s development and console and re-released the unit to the public during 1981 with the BASIC game cartridge included with the console using the name Bally Computer System which would again be renamed during 1982 to the Bally Astrocade. The system continued to be released under the name Bally Astrocade until the video game market collapse in 1983 and the console eventually disappeared entirely by the year 1985.

While the console had been under the control of Midway the company had been planning to release and additional expansion system to the console entitled the ZGRASS-100 which was under development by programmers from Nutting and “Circle Graphics Habitat” which was a group of computer artists based in the University of Illinois at Chicago. The Midway company believed the system expansion in an external case would help to generate interest in the Astrocade in the marketplace, however the addition was not yet completed and ready for commercial release at the time when Bally sold the division to the third party developers.

It is believed however that a small number of the expansions were created and released after the console was re-released under developers of the Astrovision under the name ZGRASS-32. Despite the near death of this console expansion it would later be released in a single unit called the Datamax UV-1with a shift in target audience from the original home computer market to the market of a system used for the output of high graphics to videotape. The Datamax UV-1 was released between the years of 1980 and 1982 however the data on the number of consoles which were actually built, released, and sold is not readily available.

System Description:

In the 1970’s Dave Nutting was contracted by Midway with the task of creating a video chip display which would be compatible in all of the company’s video game systems from their classic arcade machines all the way to their in home consoles. The chip which Nutting ended up creating turned out to be one of the most powerful graphics systems of the entire 8 bit generation and would be used in Midway’s most successful games of this time period including favorites like Gorf and Wizard of Wor.

The Astrocade console systems were powered using a Zilog Z80 to drive Nutter’s video chip using a RAM buffer between the components. Nutter’s video chip was also interesting because it was capable of using two different modes. One mode was low resolution and used a 160 x 102 display while the other was a high resolution display capable of producing a 320 x 204 resolution. Both the high and low resolution options used 2 bits per pixel for four colors used to make the graphics. This way of handling the graphics was revolutionary at the time and surpassed the available technology present in RAM which was incapable of keeping up with reading the data quickly enough to maintain pace with the televisions. In order to solve this problem the chip would “hold RAS high” allowing it to read a single line at a time very quickly which was fed into a buffer inside the chip. This allowed the lines to be read a more relaxed pace while using a smaller amount of available memory as well as less interference with the consoles CPU. Despite having Nutter’s incredibly advanced video chip available the chips used to produce the Astrocade did not include the necessary pins to allow the system to output the high resolution graphics which resulted in the Astrocade outputting the low resolution mode of 160 x 102, 2 bits and 4080 bytes of memory to uphold the screen which is very disappointing when better technology was easily available. The Astrocade console itself only contained 4k of RAM leading to a very small amount of space for the programming’s use which controlled aspects such as keeping track of score and game options making it necessary for the remainder of the program to be stored in ROM.

The Astrocade console used color registers/color indirection in order to allow the four colors to be selected from a palette consisting of about 256 colors. In order to modify the colors on the screen for color animation required changing the color register and the use of a horizontal blank interrupt which could be modified from line to line. It was also possible for four new colors to be swapped in at anytime which could be used in order create different halves of the screen and was originally intended to be used to simply set of a score area on the edge of the screen and some intelligent designers would use this capability in order to emulate  8 color models rather than simply four.

A major shortcoming of the Bally Astrocade was that unlike its competitor the Atari the Bally did not incuide computer graphics support. The Astrocade did however include a blitter-like system and the software rquired to drive it. The console memory which was above 0x4000 was left for the use of the display while the memory below that was left for the ROM’s usage. If a program was to write on the ROM’s space which would not normally be possible since it is “read only” then the video chip would take that data and apply a function to it and then copy it to the necessary location within the RAM. The determination of which function to use was stored in a register in the display chip and included standard instructions including XOR and bit-shift allowing the Astrocade any variety of computer graphics support/sprites without any additional hardware, the only issue was that the software would have to redraw them whenever they moved.

The Astrocade was amongst the early cartridge consoles and its games were released on special cartridges called videocades which were very similar to cassette tapes in both their size and appearance. The Astrocade unit itself however was released with two games programed directly into the ROM. The games and software that was hardwired into the console included Gunfight and Checkmate as well as a calculator program and a drawing program called Scribbling. The controllers for the Astrocade were quite complicated and also unique compared to other controller used by its competitors. The controller resembled a pistol type grip including a trigger switch on the front, a fours switch and eight directional joystick which was located on top of the grip, and the shaft of the joystick was capable of being rotated to use like the earlier paddle controllers. These controllers were well received by the public and the only complaint tended to be the fact that they were delicate and prone to breaking. The front of the actual console also contained input devices in the form of a 24 “hex-pad” keyboard that players used to select their games and settings. In general most of the videocades contained two games and upon being attached to the console it would restart a show a menu listing the two games on the cartridge and the hardwired games and programs to select from. The back of the console had a variety of ports for controllers, power, and an expansion port. The console also had an empty space which was intended to hold up to 15 videocades for storage. The Astrocade‘s capability to be upgraded from a video game console into a Person Computer  and its library consisting of about 30 games made this system far more versatile and unique than most of its competitors.


The Astrocade also included a BASIC programming language cartridge which was based upon Lee Chen Wang’s work on Palo Alto Tiny BASIC. Actually using BASIC could prove to be difficult because it required the use of the entire display and the majority of the system’s available RAM. The BASIC programs were stored in the video RAM by interweaving every bit of the program around the display space with BASIC using all the even-numbered bits and the display using the odd-numbered bits. The code interpreter would then read 2 bytes and drop the odd numbered bits to assemble a single byte of code. The BASIC was very slowly and painstakingly programmed using the keyboard attached to the console assigning each of the keys a command, a number, and several alphanumeric symbols which were selected between by four different colored shift keys.


The ZGRASS unit would sit beneath the actual Astrocade console and effectively turned the game system into a real computer including a keyboard, a math co-processor, 32k of RAM, and a new 32k of ROM containing the GRASS/GRAFIX programmable language. The unit also included ports to allow the use of floppy discs and cassettes.

Available Games:

– 280 Zzzap/Dodgem

– Amazing Maze/ Tic Tac Toe

– Artillery Duel

– Astro Battle (also called Space Invaders)

– Bally Pin


– Baseball

– Basketball

– Bingo Math/ Speed Math

– Biorhythm

– Blackjack/ Poker/ Acey Duecey

– Blast Droids

– Bowling

– Checkers/ Backgammon

– Clowns/ Brickyard

– Coloring Book

– Conan the Bararian

– Cosmic Raiders

– Dog Patch

– Drag Race/ Desert Fox

– Football

– Galactic Invasion (Galaxiian)

– Grand Prix/ Demolition Derby

– Gunfight

– ICBM Attack

– Letter Match/ Spell N’ Score/ Crosswords

– Machine Language Manager (not game)

– Maze Man

– Median

– Missile Attack

– Ms. CandyMan

– Muncher

– Music Maker

– Panzer Attack/ Red Baron

– Pirates Chase

– Sea Devil

– Seawolf/ Missile

– Soccer

– Solar Conquerer

– Space Fortress

– Space Invaders

– Star Battle

– The Incredible Wizard

– Tornado Baseball/ Tennis/ Hockey/Handball

– Treasure Cove

– War


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