Coleco Gemini
 | |
| Coleco Gemini with a Dual Command controller (Evan-Amos, public domain) | |
| Specifications | |
|---|---|
| Manufacturer | Coleco Industries (made in Taiwan) |
| Type | Home video game console, Atari 2600 compatible |
| Released | 1983[1] |
| Intro price | US$60 (Sears, 1983)[2] |
| CPU | 6507 (Synertek SY6507 on the board photographed)[3][4] |
| Memory | RAM in the 6532 RIOT[3] |
| Storage | — |
| Display | RF output on channel 2 or 3[5] |
| Sound | From the TIA-compatible chip, through the TV[3] |
| Graphics | TIA-compatible chip made by VTI, marked "COLECO 73192"[3][4] |
| Media | Atari 2600 (VCS) cartridges[5] |
| Input | Two controller sockets; Dual Command joystick and paddle controllers[5] |
| Power | 9 V DC adapter (Coleco 91617), regulated to 5 V on the board[3][4] |
| OS / Firmware | — |
| Model no. | 2510 |
The Coleco Gemini (model 2510) is Coleco's 1983 video game console for Atari 2600 cartridges. It contains the same three main parts as the Atari machine, a 6507 processor, a 6532 RIOT and a chip that does the job of Atari's TIA, but the TIA-compatible chip was made for Coleco by VTI. The Gemini is much smaller than the 2600 and has its own controllers, each combining a joystick and a paddle.[3][5][2]
History
[edit | edit source]Coleco's ColecoVision Expansion Module No. 1 of 1982 let the ColecoVision play Atari 2600 games, using a TIA clone and standard parts. Atari sued Coleco for patent infringement, and the two settled out of court in March 1983 with Coleco becoming a licensee of Atari's patents. Under the settlement Coleco could go on making both the module and the stand-alone Gemini.[1][2] The Gemini was first bundled with Coleco's own Donkey Kong cartridge, and later with other Coleco titles.[1]
Sears's 1983 Christmas catalogue sold the Gemini beside the Atari 2600, both at US$60. Columbia House sold a rebadged version, the Columbia House Home Arcade, through its video game club.[2]
Hardware
[edit | edit source]| Position | Part |
|---|---|
| U1 | 6507 CPU (Synertek SY6507) |
| U2 | 6532 RIOT: RAM, I/O ports and timer (Synertek SY6532) |
| U3 | TIA-compatible video and sound chip, VTI, marked "COLECO 73192 E4002" |
| U5 | 7805 +5 V regulator on a heatsink |
| C34 | 2200 µF 16 V axial electrolytic, beside the regulator |
| Y1 | Crystal |
Positions and markings are read from Evan-Amos's photograph of a board marked "CPC-2 94V-1, Made in Taiwan R.O.C.";[4] Leaded Solder's restoration describes the same three chips and a 7805 on a single-sided board marked CPC-2, Rev F, copyright 1983.[3] The photographed board has a µA7805UC made in Korea; Leaded Solder's has a National Semiconductor 7805.[4][3]
The board also carries the RF modulator, the two controller sockets, the cartridge connector and seven switches.[4]
Controls and connections
[edit | edit source]- Top of the console: ON/OFF power, COLOR/B&W, GAME SELECT and RESET.
- Front edge: left and right DIFFICULTY switches, between the two controller sockets.
- Rear: CHANNEL 2-3 selector, the game cable socket and the power socket.
- Right-hand side of the top: the cartridge slot. The cartridge goes in with its front label facing the back of the console.[5]
Each Gemini controller has an eight-direction joystick, a side button that does the job of the red button on an Atari joystick, and a paddle knob. For paddle games both controllers plug into a WYE connector in the left socket; with two WYE connectors and four controllers the Gemini plays four-player games. Coleco states that any controller that works on the Atari VCS works on the Gemini.[5]
The power adapter is Coleco part 91617, 9 V DC with a centre-positive plug like the Atari 2600's.[3] Coleco's manual says to connect it only to a 110/120 V outlet and to unplug it after play.[5]
Known faults
[edit | edit source]David Farquhar gives broken solder joints as the most likely fault on a dead Gemini.[2] Leaded Solder's Gemini had cracked joints on both controller sockets, a cracked joint on the DC jack and an underfilled factory joint on the TIA clone; its fault list was unreliable power and dead controllers, both cured by reflowing.[3] Details are on Coleco Gemini Troubleshooting Guide.
Documentation
[edit | edit source]- Coleco Gemini Owners Manual: Coleco's owners manual, Guide No. 91783A (1983), with a troubleshooting checklist.
Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 1.2 Wikipedia, "Coleco Gemini" (retrieved 2026-10-06), for history only: 1983 release; Expansion Module No. 1 and the Atari lawsuit; the settlement reported by the Associated Press on 13 March 1983 allowing Coleco to continue making the module and the Gemini as a licensee of Atari's patents; the controller name "Dual Command"; the pack-in games.
- ↑ 2.0 2.1 2.2 2.3 2.4 David L. Farquhar, "Coleco Gemini: An Atari 2600 clone from 1983", The Silicon Underground, 31 July 2017, updated 20 June 2025 (retrieved 2026-10-06): the VTI TIA clone; Atari's suit of December 1982 and the settlement of March 1983; the Gemini and the 2600 both at $60 in Sears's 1983 Christmas catalogue; the Columbia House Home Arcade version; broken solder joints as the most likely fault.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 "Space Walking with Gemini", Leaded Solder, 6 April 2020, leadedsolder.com (retrieved 2026-10-06). Restoration of a Canadian Gemini: single-sided board marked CPC-2, Rev F, 1983; 6507, MOS 6532 RIOT and VTI TIA clone, plus a National Semiconductor 7805; two polystyrene capacitors; cracked solder joints on both controller ports, an underfilled joint on the TIA clone and a cracked joint on the DC jack; adapter Coleco 91617, 9 V DC centre-positive with the same plug as the Atari 2600; RF modulator; cartridge contacts cleaned with alcohol.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Evan-Amos, photograph of a Coleco Gemini main board, 17 May 2018, from Wikimedia Commons (public domain): silkscreen "CPC-2 94V-1, Made in Taiwan R.O.C."; U1 Synertek SY6507 (8311), U2 Synertek SY6532 (8311), U3 "COLECO 73192 E4002" with the VTI logo (8310), U5 µA7805UC on a heatsink, C34 2200 µF 16 V axial, Y1, switches S1–S7, RF modulator can.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Coleco Industries, Gemini Video Game System Owners Manual, model 2510, Guide No. 91783A, 1983: pp. 3–6 (antenna switch box, game cable, power supply, channel 2-3 selector), p. 7 (inserting the cartridge; console switches), p. 8 (starting play; difficulty switches), p. 9 (the two-way hand controllers; WYE connector; any Atari VCS controller works), pp. 10–11 (troubleshooting checklist), p. 12 (care), p. 13 (warranty), p. 15 (accessories). Hosted here as File:Coleco Gemini Owners Manual Guide 91783A.pdf (see Coleco Gemini Owners Manual).
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