Bally Astrocade

It was marketed only for a limited time before Bally decided to exit the market. The rights were later picked up by a third-party company, who re-released it and sold it until around 1984. The Astrocade is particularly notable for its powerful graphics capabilities for the time of release, and for the difficulty in accessing those capabilities.

• Name — Bally Astrocade • Aka — Bally Professional Arcade (1978–81) Bally Computer System (1981–82) • Manufacturer — Bally Manufacturing Astrovision • Type — Home video game console • Generation — Second generation • Release Date — April 1978 • Discontinued — 1983 • Cpu — Zilog Z80 clocked at 1.789 MHz • Memory — 4 KB–64 KB (with external modules) RAM 8 KB ROM • Memory Card — ROM cartridge • Graphics — 160×102 or 320×204 in 4/8 colors

In the late 1970s, Midway contracted Dave Nutting Associates to design a video display chip that could be used in all of their videogame systems, from standup arcade games, to a home computer system. The system Nutting delivered was used in most of Midway's classic arcade games of the era, including Gorf and Wizard of Wor. The chipset supported what was at that time relatively high resolution of 320×204 in four colours per line, although to access this mode required memory that could be accessed at a faster rate than the common 2 MHz dynamic RAM of the era.

Originally referred to as the Bally Home Library Computer, it was released in 1977 but available only through mail order. Delays in the production meant none of the units actually shipped until 1978, and by this time the machine had been renamed the Bally Professional Arcade. In this form it sold mostly at computer stores and had little retail exposure, unlike the widely available Atari VCS. In 1979, Bally grew less interested in the arcade market and decided to sell off their Consumer Products Division, including development and production of the game console. At about the same time, a third-party group had been unsuccessfully attempting to bring their own console design to market as the Astrovision. A corporate buyer from Montgomery Ward who was in charge of the Bally system put the two groups in contact, and a deal was eventually arranged. In 1981, they re-released the unit with the BASIC cartridge included for free, this time known as the Bally Computer System, with the name changing again in 1982 to Astrocade. It sold under this name until the video game crash of 1983, and then disappeared around 1985. Midway had long been planning to release an expansion system for the unit, known as the ZGRASS-100. The system was being developed by a group of computer artists at the University of Illinois at Chicago known as the 'Circle Graphics Habitat', along with programmers at Nutting. Midway felt that such a system, in an external box, would make the Astrocade more interesting to the market. However it was still not ready for release when Bally sold off the division. A small handful may have been produced as the ZGRASS-32 after the machine was re-released by Astrovision. The ZGRASS system, combined into a single box, would eventually be released as the Datamax UV-1. Originally aimed at the home computer market while it was being designed, the UV-1 was re-targeted as a system for outputting high-quality graphics to videotape. These were offered for sale some time between 1980 and 1982, but it is unknown how many were built.

The Astrocade also included a BASIC programming language cartridge, written by Jamie Fenton, which was an expanded version of Li-Chen Wang's Palo Alto Tiny BASIC. First published as Bally BASIC in 1978. Developing a BASIC interpreter on the system was difficult, because the display alone used up almost all the available RAM. The solution to this problem was to store the BASIC program code in the video RAM. This was accomplished by interleaving every bit of the program along with the display itself; BASIC used all the even-numbered bits, and the display used the odd-numbered bits. The interpreter would read out two bytes, drop all the odd-numbered bits, and assemble the results into a single byte of code. This was rendered invisible by setting two of the colors to be the same as the other two, such that colors 01 and 11 would be the same (white), so the presence, or lack, of a bit for BASIC had no effect on the screen. Additional memory was scavenged by using fewer lines vertically, only 88 instead of the full 102. This managed to squeeze out 1760 bytes of RAM for BASIC programs. The downside was that most of the graphics system's power was unavailable. Programs were entered via the calculator keypad, with a plastic overlay displaying letters, symbols, and BASIC keywords. These were selected through a set of 4 colored shift keys. For example; typing "WORD"(gold) shift then the "+" key would result in GOTO. A simple line editor was supported. After typing the line number corresponding to an existing program, each press of the PAUSE key would load the next character from memory. An Astro BASIC program that later became commercialized is Artillery Duel. John Perkins wrote the game first and submitted it to The Arcadian fanzine, from which it was adapted for the Astro BASIC manual. Perkins subsequently developed the Astrocade cartridge of the game.

Astro BASIC supported the following keywords: • Commands: LIST, RUN, STOP, TRACE • Statements: PRINT, INPUT • Structure: GOTO, GOSUB, RETURN, IF (but no THEN and no ELSE), FOR-TO-STEP/NEXT • Graphics: BOX, CLEAR, LINE • Tape Commands:PRINT:INPUT:LIST:RUN • Functions: ABS, CALL, JX (specified joystick's horizontal position), JY (joystick vertical position), KN (knob status), PX(X,Y) (pixel on or off), RND, TR (trigger status) • Built-in variables • (read only): KP (key press), RM (remainder of last division), SZ (memory size), XY (last LINE position) • (write only): SM= (scroll mode), TV= (display ASCII character) • (read/write): BC (background color), CX CY (cursor position), FC (foreground color), NT (note time), • Math: + - × ÷ • Relational operators: = = # [not equal] [the language did not support <>] • Logical operators: × [AND] + [OR] A period. at the start of the line was equivalent to REM in other BASIC implementations. Certain commands were handled by the keypad instead of by keywords: the RESET button was equivalent to NEW in other interpreters. The language supported 26 integer variables A to Z, and two pre-defined arrays, @ - which was stored starting after the program, ascending - and * - which was stored from the top of memory, descending. The language lacked a DIM statement for dimensioning the arrays, the size of which was determined by available memory (SZ) not used by the program listing (2 bytes per item). Ports were accessed via the array &, and memory was accessed via the array %, rather than using PEEK and POKE. While the language lacked strings, KP would provide the ASCII value of a key press, which could be output to TV, meaning that characters could be read in from the keyboard, stored in an array, and then output. The character display was 11 lines of 26 characters across. The resolution for the graphic commands is 88x160, with X ranging from -80 to 79 and Y ranging from -44 to 43. Music could be produced in four ways: • The PRINT command, as a side effect, produced a unique tone for each character or keyword displayed. • The MU variable converted numbers into notes. • Ports 16 through 23 accessed a music synthesizer. • The sound-synthesizer variables MO (master oscillator), NM (Noise Mode), NV (Noise Volume), TA (Tone A), TB (Tone B), TC (Tone C), VA (Voice A volume), VB (Voice B volume), VC (Voice C volume), VF (Vibrato Frequency), VR (VibRato). (Added to Astro BASIC but not in Bally BASIC.)

The following sample program from the manual demonstrates the joystick input and graphics functions. "Try your skill... The first player's knob moves the phaser left or right and the trigger shoots... Player two controls the target while player one shoots." 1= 1.PHASER PHUN 2.BY DICK AINSWORTH 10 2=cbmbas 20 2=cbmbas 30 CLEAR 40 X=X+JX(2)×3 50 Y=Y+JY(2)×3 60 BOX X,Y,4,4,3 70 K=KN(1)÷2 80 BOX K,-40,3,8,1 90 100 N=1 110 2=cbmbas 120 2=cbmbas 130 BOX K,0,1,80,3 140 MU="4" 150 BC=A×8 160 170 FC=7 180 BC=8 190 This listing illustrates how keywords, which were tokenized, were always displayed with a following space.

The ZGRASS unit sat under the Astrocade and turned it into a "real" computer, including a full keyboard, a math co-processor (FPU), 32k of RAM, and a new 32k ROM containing the GRASS programming language (sometimes referred to as GRAFIX on this machine). The unit also added I/O ports for a cassette and floppy disk, allowing it to be used with CP/M.

• Illustration — Bally Astrocade motherboard

• CPU: Zilog Z80, 1.789 MHz • RAM: 4 kB (up to 64 kB with external modules in the expansion port) • ROM: 8 kB • Cart ROM: 8 kB • Expansion: 64 kB total • Ports: 4 controller, 1 expansion, 1 light pen

• Illustration — Demonstration of Bally Arcade's multi-voice sound chip, including noise and various vibrato effects • Sound chip model: 0066-117XX, also known as the Music Processor, or a custom I/O chip since the sound chip also performs I/O functions. • Channel capabilities: There are 3 square wave channels, all with a pitch accuracy of 8-bits (256 possible frequencies from which to choose), which can all play square waves. The chip also has a noise generator, which can be independent from the other 3 square wave channels, or it can add its value to the master oscillator that drives the 3 square wave channels. The master oscillator can be set to different frequencies, which means that the frequency range can be changed for the 3 square wave channels. • Volume control: Each channel has independent 4-bit volume control. • Miscellaneous features concerning sound: There are hardware registers for vibrato, with two bits for the vibrato speed and 6 bits for vibrato depth. This means that it wouldn't be necessary for vibrato to be done entirely with software.

• Resolution: True 160×102 / Basic 160×88 / Expanded RAM 320×204 • Colors: True 8* / Basic 2 • The bitmap structure of the Bally actually only allows for 4 color settings. However, through the use of 2 color palettes and a left/right boundary control byte, the left section of screen (this could be the play field) could use one set of colors while the right side (this could show information such as lives and score) could use an entirely different set of colors, thus 8 total colors could possibly be displayed at once. • Graphic type: Bitmap, 2 bit per pixel bit map.

There were 31 cartridges released for the system before its discontinuation. Many of these cartridges provide two or more games bundled together. Counted separately and including the four games built into ROM, there were a total of 51 games and software applications released in this format. Later on, a number of games were published by unlicensed third parties, many of whom had gotten their start developing BASIC programs for the Astrocade as underground developers. These developers also released these BASIC games on cassette tapes and in print through the Arcadian newsletter. Many early games were licensed ports of Bally Midway arcade games, including Space Invaders and Galaxian which were licensed to Bally Midway for the North American market. Some of these titles had to be later changed due to licensing issues.

• Title — No. — Publisher — Release — Description • 280 Zzzap — 2001 — Bally — Based on Midway's 1976 arcade racing game • Acey-Deucey — 5002 — Bally — A card betting game, unrelated to the board game despite the name • Amazing Maze — 5001 — Bally — Based on Midway's 1976 arcade maze game • Artillery Duel — 5005 — Astrovision — An artillery game • Bally BASIC — 6004 — Bally — A BASIC interpreter • Bally Pin — 3005 — Bally — A pinball video game • Bingo Math — 4001 — Bally — An educational math game • Biorhythm — 4004 — Astrovision — A biorhythm calculator • Blackjack — 4004 — Bally — Based on the card game blackjack • Brickyard — 2004 — Bally — Similar to Atari's Breakout • Blast Droids — Esoterica — A multidirectional shooter, similar to Midway's Omega Race • Blue Ram BASIC — Perkins Engineering — An extended version of BASIC sold with The Blue Ram, a third party RAM expansion • Calculator — Bally — An arithmetic calculator • Checkmate — Bally — Based on Midway's 1977 arcade snake game • Clowns — 2004 — Bally — Based on Midway's 1978 arcade circus game • Cosmic Raiders — 2019 — Astrovision — A scrolling shooter, Similar to William's Defender • Crosswords — 4002 — Bally — A letter arrangement game • Demolition Derby — 2014 — Astrovision — Based on the sport of demolition derby • Dodgem — 2001 — Bally — A topdown racing game • Dog Patch — 2010 — Bally — Based on Midway's 1978 arcade skeet shooting game • Football — 3002 — Bally — Based on the sport of American football • Galaxian — 2007 — Astrovision — Based on Namco's 1979 arcade shoot 'em up • Grand Prix — 2014 — Astrovision — An overhead racing game • Gun Fight — Bally — Based on Midway's 1975 arcade wild west game • Handball — 3001 — Bally — Similar to Pong but based on the sport of handball • Hockey — 3001 — Bally — Similar to Pong but based on the sport of ice hockey • I.C.B.M. Attack — Spectre Systems — Similar to Atari's Missile Command • Letter Match — 4002 — Bally — Based on the card game concentration • Machine Language Manager — Bit Fiddlers — A development environment for writing machine code • Missile — 2002 — Bally — Based on Midway's 1977 arcade shooting game Guided Missile • Ms. Candyman — L&M Software — Similar to Midway's Ms. Pac-Man • Muncher — Esoterica — Similar to Namco's Pac-Man • Panzer Attack — 2003 — Bally — A tank game, similar to Atari's Combat • Pirates Chase — 2015 — Astrovision — A maze chase game with no maze • Poker — 5002 — Bally — Based on the card game poker • Red Baron — 2003 — Bally — A dogfighting game, similar to Atari's Combat • Scribbling — Bally — A basic drawing program • Sea Devil — L&M Software — an underwater scrolling shooter, similar to William's Defender • Seawolf — 2002 — Bally — Based on Midway's 1976 submarine game • Sneaky Snake — New Image — Similar to Atari's Centipede • Solar Conqueror — 2018 — Astrovision — A multidirectional shooter • Space Fortress — 2012 — Astrovision — Based on Midway's 1980 arcade shoot 'em up Space Zap • Space Invaders — 2008 — Bally — Based on Taito's 1978 arcade shoot 'em up • Speed Math — 4001 — Bally — An educational math game • Spell ‘n Score — 4002 — Bally — A letter arrangement game • Star Battle — 2005 — Bally — A rail shooter, similar to Atari's Star Wars arcade game • Tennis — 3001 — Bally — Similar to Pong but based on the sport of tennis • The Incredible Wizard — 2017 — Astrovision — Based on Midway's 1981 arcade maze game Wizard of Wor • Tic-Tac-Toe — 5001 — Bally — Based on the pen and paper game tic-tac-toe • Tornado Baseball — 3001 — Bally — Based on Midway's 1976 arcade baseball game • Treasure Cove — Esoterica — A scuba diver game

• Conan the Barbarian • Mazeman • Soccer • Fawn Dungeon