Coleco Telstar Gemini
 | |
| A Telstar Gemini with its pistol and box (photographs published on the VideoGames Console blog). No freely licensed photograph of the Gemini has been found. | |
| Specifications | |
|---|---|
| Manufacturer | Coleco Industries, Inc.[1] |
| Type | Dedicated home video game console (pinball and target shooting) |
| Released | 1978[1][2] |
| CPU | None; one MOS Technology MPS 7600-series game chip[1][3] |
| Memory | 512-word ROM inside the game chip (MPS 7600 series)[4] |
| Storage | None |
| Display | Colour, on a television set[5] |
| Sound | Built-in beeper[1] |
| Input | Two flipper buttons, launch button, three playfield sliders, pistol[1][5] |
| Power | 9 V battery or AC adapter, according to a collector site[2] |
| OS / Firmware | — |
The Coleco Telstar Gemini is a dedicated TV game made by Coleco and dated to 1978. It plays four pinball games and two target shooting games in colour.[1][5] It has no paddle knobs or joysticks.[2] A flipper button sits on each side of the case, a large red button launches the ball, three sliders move the bumpers and chutes of the playfield, and a pistol is used for the target games.[1][5] The six games are the same as those on Cartridge No. 3 for the Telstar Arcade.[6]
The Telstar Gemini is a different machine from the Coleco Gemini, Coleco's later Atari 2600-compatible console.
History
[edit | edit source]Arcade-History and Retro Gaming Consoles both date the Gemini to 1978.[1][2] Pong-Story names it, with the Galaxy, the Combat! and the Arcade, among the few Telstars not built on General Instrument's AY-3-8500.[7] Coleco had already sold the same six games for the Telstar Arcade: its 1977 order flyer offers Cartridge No. 3 (model 6113) at $25.00 by mail, with four pinball games and two target games in colour.[8] The Gemini's box calls them "6 video games in color" and lists "authentic flipper action", "electronic pinball sounds" and "digital display scoring".[5]
Hardware
[edit | edit source]| Part | Detail |
|---|---|
| Game chip | "Coleco MPS 7600" (Arcade-History); "a MOSTEK chip" (Pong-Story)[1][7] |
| Games | Bonus Pinball and Deluxe Pinball, each for one or two players; Shooting Gallery; Shoot the Bear[1] |
| Picture | Colour[5][1] |
| Sound | Built-in beeper[1] |
| Pinball controls | A flipper button on each side; a red launch button; three playfield sliders[1][9] |
| Gun | Revolver-shaped pistol; Arcade-History calls it a rifle[9][5][1] |
| Power | A 9 V battery or an AC adapter, according to Retro Gaming Consoles[2] |
Pong-Story's description of the chip as a Mostek part conflicts with its own Arcade page and with Arcade-History, which both name MOS Technology's MPS 7600.[7][3][1] The Centre for Computing History identifies the chip in Telstar Arcade Cartridge No. 3, which plays the same six games, as the MPS 7600-004.[10][6] No photograph of the Gemini's board has been published, so the suffix on the Gemini's own chip is unconfirmed.
MOS Technology's 1976 specification for the first chip in the series, the MPS 7600-001, describes a frame processor run by a mask-programmed 512-word ROM, so that each version of the chip carries its own games.[4] The chip needs a single supply of -6.5 to -9.5 V, a crystal at 3.579545 MHz (or 3.595314 MHz for cheaper "rainbow" colour), potentiometers for the player controls and a one-transistor sound amplifier. For target games it needs a gun with a trigger switch and a photoelectric detector feeding the chip's HIT input.[4]
Controls
[edit | edit source]Arcade-History describes the pinball controls as follows.[1]
- The two flipper buttons, one on each side of the case, work the flippers.
- The large red button launches the ball. A short tap sends it out slowly and a long press sends it out fast.
- Three sliders on the left of the console move the bumpers and chutes up and down, so the ball behaves differently from one game to the next.
The photograph of a Gemini on the VideoGames Console blog shows the three sliders at the back left of the top, the red launch button at the front right, a red button on the right-hand side, and a metal-faced control panel with a large rotary knob, two small lever switches and three small round fittings. The panel's legends cannot be read at the size published.[9]
On the Telstar Arcade the same games take the flippers from the LEFT SLAM button and the launch from the RIGHT SLAM button. The playfield adjustments come from the Arcade's two rotary paddle controls and its steering wheel: the left control moves the large chutes, the steering wheel the large side bumpers, and the right control the small chutes and small bumpers.[11] Video magazine's 1979 test of the Arcade noted that in pinball the paddle knobs or the steering wheel modify the playing field.[12] On the Gemini the three sliders do those three jobs.[1]
Games
[edit | edit source]Coleco's rules for Cartridge No. 3 give each pinball player three balls. The playfield is set before the game starts, RESET starts play, and the balls appear after a short wait. Regular bumpers, hot shot bumpers, chutes and alleys score 1 point, special rollovers 2 and bonus targets 3. A ball entering a chute lights the rollovers and a ball entering an alley lights the bonus targets; those points are added after the ball leaves the playfield.[11] Shooting Gallery has fixed targets and Shoot the Bear has moving "bears".[6]
Power
[edit | edit source]Retro Gaming Consoles says the Gemini runs from a 9 V battery or from an AC adapter, and that the adapter stows in the base of the unit.[2] No Coleco document confirming the battery type or the adapter model has been found.
Repair
[edit | edit source]No service information or repair report for the Gemini has been published. Its guides use Coleco's rules for the same games on the Arcade and MOS Technology's data for the MPS 7600 series:
- Coleco Telstar Gemini General Maintenance: the flipper and launch buttons, the playfield sliders, the pistol and the battery compartment.
- Coleco Telstar Gemini Troubleshooting Guide: symptoms, normal game behaviour, and reference values for the MPS 7600 series.
- Coleco Telstar Gemini Capacitor Replacement Guide: what is known about the capacitors and how to record your own board's parts.
Documentation
[edit | edit source]Coleco's instruction guide for the Gemini has not been found online. The first page of Coleco's rules for Telstar Arcade Cartridge No. 3 (Guide No. 76634), which covers the same games, is hosted as File:Coleco Telstar Arcade Cartridge No. 3 game rules, first page (Guide 76634).jpg.[11] MOS Technology's MPS 7600-001 specification is described on Coleco Telstar Arcade Documentation.[4]
Gallery
[edit | edit source]-
The Gemini's box (Pong-Story) -
Coleco's 1977 flyer for Telstar Arcade Cartridge No. 3, showing the screens of the six games the Gemini also plays -
Coleco's rules for Cartridge No. 3, first page, with the playfield diagram
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Related pages
[edit | edit source]- Coleco Telstar Arcade, whose Cartridge No. 3 plays the same games
- Coleco Telstar Marksman, a Telstar of 1978 with a light gun
- Coleco Gemini, the unrelated Atari 2600-compatible console
- Category:Coleco
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 Arcade-History, "Telstar Gemini" (retrieved 2026-10-19): Coleco, 1978; plays two shooting games and four pinball games instead of the common Pong games; games Bonus Pinball and Deluxe Pinball for one or two players, Shooting Gallery and Shoot the Bear; two flipper buttons, one on each side of the console; a big red button on top launches the ball, a short tap sending it out slowly and a long press fast; three sliding knobs on the left side move the playfield's bumpers and chutes up and down; controllers: the two pinball buttons and a rifle for the shooting games; CPU "Coleco MPS 7600"; colour; built-in beeper.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Retro Gaming Consoles, "Coleco Telstar" (retrieved 2026-10-19): the Gemini, released in 1978, has two gun games and four pinball games, no paddles or joysticks, flipper buttons at the left and right sides and a large red button at the front to launch the ball; "powered by a 9 volt battery, it could also be powered using an ac adaptor, which handily fitted into the base of the unit".
- ↑ 3.0 3.1 David Winter, Pong-Story, "Coleco Telstar Arcade" (retrieved 2026-10-18): each Arcade cartridge contains a chip made by MOS Technology, the MPS-7600; the four versions contain circuits customised for their types of game, all built round a basic frame processor driven by a small program in ROM.
- ↑ 4.0 4.1 4.2 4.3 MOS Technology, Specification for Video Game Array MPS 7600-001, preliminary, rev. 1, June 1976, pp. 7 and 9-12 and Figure 4.1A, File:MOS Technology MPS 7600-001 Video Game Array Specification (1976).pdf: a mask-programmed series (MPS 7600-XXX) built round a frame processor with a 512-word ROM; crystal clock of 3.579545 MHz (full colour) or 3.595314 MHz ("rainbow" colour), one of which is essential to stable operation; a single supply of -6.5 to -9.5 V, with two VDD and two VSS pins that must all be connected; most designs battery powered, and an AC supply needs adequate current and filtering because sharp transients "may result in perturbations of the game display"; four player-control inputs (P1 to P4 in Figure 4.1A), each a potentiometer, and the controls "receive considerable abuse"; sound through a single-transistor amplifier driving the speaker; the target games need a gun with a trigger switch in the control matrix and a photoelectric circuit sending pulses to the HIT pin; on the -001, special logic rejects false hits from room lighting, reflections or aiming at light sources.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Box photograph on Pong-Story, File:Coleco Telstar Gemini box (Pong-Story).gif: TELSTAR GEMINI, "6 video games in color", "4 pinball games", "2 moving target games"; authentic flipper action, electronic pinball sounds, digital display scoring; the box art shows the console and a pistol.
- ↑ 6.0 6.1 6.2 David Winter, Pong-Story, "Coleco Telstar Arcade - Cartridge #3" (retrieved 2026-10-19): Cartridge #3 plays six games, four pinball games (Bonus Pinball and Deluxe Pinball, each for one or two players), Shooting Gallery (fixed targets) and Shoot the Bear (moving "bears"); it uses only the console's knobs and pistol; "The games of this cartridge are same as those of the Telstar Gemini system."
- ↑ 7.0 7.1 7.2 David Winter, Pong-Story, "Coleco Telstar systems" (retrieved 2026-10-18): all the Telstars were based on GI's AY-3-8500 except a few models, including the Telstar Galaxy, Telstar Combat, Telstar Gemini "(which used a MOSTEK chip)" and the Telstar Arcade, "which used MOSTEK chips in plugin cartridges"; a small photograph of the Gemini's box.
- ↑ Coleco Industries, Telstar Cartridges order flyer, part no. 76627, 1977, File:Coleco Telstar Arcade Cartridge 3 order flyer (Part No. 76627).jpg: "6113 Telstar Arcade Cartridge #3", six games in colour, four pinball and two target; screen pictures of Bonus Pinball (one and two players), Shooting Gallery, Shoot the Bear and Deluxe Pinball (one and two players); $25.00 by mail.
- ↑ 9.0 9.1 9.2 Photographs published on the VideoGames Console blog, "Coleco Telstar Gemini" (11 January 2009), File:Coleco Telstar Gemini with pistol and box.jpg: the console has three slider knobs at the back left of the top, a metal-faced control panel at the front with a large rotary knob, two small lever switches and three small round fittings, a large red square button at the front right and a red button on the right-hand side; the gun is a revolver-shaped pistol.
- ↑ Centre for Computing History, "Coleco Telstar Arcade", reference CH66264 (retrieved 2026-10-19): Telstar Arcade Cartridge 3 (Bonus Pinball, Shooting Gallery, Shoot the Bear and Deluxe Pinball) uses the chip MPS 7600-004.
- ↑ 11.0 11.1 11.2 Coleco Industries, Game Rules and Operation of Telstar Cartridge No. 3, Model No. 6113, Guide No. 76634, p. 1, photographed by Pong-Story, File:Coleco Telstar Arcade Cartridge No. 3 game rules, first page (Guide 76634).jpg: "Plays 6 video games in color": four pinball games with flipper control and two moving target games; flippers are worked by the LEFT SLAM button and the ball plunger by the RIGHT SLAM button, "a very short 'tap' will shoot the ball out slowly" and "a longer 'press' will shoot the ball out faster"; the steering wheel and the right and left rotary control knobs move the play field's bumpers and rollover chutes up and down (large chutes on the left rotary control, large side bumpers on the steering wheel, small chutes and small bumpers on the right rotary control); set the play field before starting; press RESET and wait for the balls to appear; three balls per game; scoring: regular bumper 1 point, chutes and alleys 1, hot shot bumper 1, special rollovers 2, bonus targets 3, with rollover and bonus target points added after the ball leaves the play field; turn the console off before changing cartridges.
- ↑ Berger-Braithwaite Labs, "Coleco Telstar Arcade Video Game", VideoTests, Video, Spring 1979, p. 55, Internet Archive scan (retrieved 2026-10-19): on the Arcade, "in other games, like pinball, the paddle knobs or the steering wheel modify the playing field"; on a few games the testers could get the balls hung up making endless rounds of the court, or watch them go through what should have been solid sidewalls or bumpers.