A ColecoVision-compatible games console that you can build yourself!
The Leako project is licensed under the Creative Commons Attribution-NonCommercial 4.0 license.
I originally developed this board in order to play some ColecoVision games that I had gotten from the flea market. This turned into several articles on my old-computer repair blog, Leaded Solder:
- Part 1, covering the impetus and design;
- Part 2, covering the assembly and debugging.
- Part 3, covering "digital" joysticks and the Hand Controller
- Part 4, partially covering "quadrature" joysticks such as the steering wheel and Roller Controller
If you enjoyed this project or if you're interested in contributing to future development, I would greatly appreciate a subscription to the Leaded Solder Patreon. The Patreon not only helps me afford to develop expensive projects like this one, but also includes behind-the-scenes posts and previews of upcoming articles.
First, use a PCB fabrication shop such as JLCPCB or PCBWay to order a Gerber file. You can get those from the Releases page.
Stay tuned for a more involved assembly guide, but early adopters are welcome to assemble and test a board.
For the easiest build, you can install the Interactive BOM Plugin and use KiCad to export it. This will give you a click-through visual BOM that makes it really easy to assemble the board. Future versions of this board will come with one of these files in the Release.
You'll want to consult the BOM PDF for the version of the Leako board you wish to assemble. The first truly "working" version was v0.6. I recommend getting the Gerber ZIPs and BOM from the Releases page.
Not all parts on the BOM (Bill of Materials) can be obtained new. Many components are salvaged and can be obtained from eBay or other Chinese-market surplus stores such as AliExpress. Because the sellers and availability are changing constantly, I unfortunately cannot recommend a specific vendor. I suggest ordering from multiple different sellers and building more Leakos with all the leftover parts :)
For a quicker checkout process, I have constructed a Digi-Key "list" which can help you add all of the "new" parts necessary quickly.
Namely, you will need to find:
- A TI TMS9918A/TMS9918ANL (not TMS9118, TMS9119, TMS9929, or TMS9928) VDP;
- A TI SN76489 sound chip;
- A 27c512-compatible EPROM (a 27c256 may also work but has not been tested);
- ColecoVision cartridge games;
- A ColecoVision-compatible controller
Please note the Leako has, so far, only been constructed and tested in NTSC regions. A PAL version would be a very interesting conversion, but would use a chip like a TMS9919 as well as probably some other board changes.
You will also need a USB power supply and a USB-B cable. I recommend using a USB power supply capable of at least 2A - although I have only measured ~450mA max in practice, it would not be a bad idea to have some additional headroom. A lower-quality supply is also likely to introduce more noise. I have tested with two models of Anker PowerPort.
Please also note that at the time of publication, a silicon and fabrication shortage has meant that many parts (for instance, the TI TPS60403 -5V voltage inverter) have become difficult and/or more expensive to locate than when the machine was originally designed. Some have been substituted, but there are likely others.
The ColecoVision games and console rely on the presence of a BIOS ROM. In order to program the EPROM with the BIOS, you'll need a copy of the BIOS (it can be dumped from a real ColecoVision) and an EPROM programmer such as a TL866II+.
For soldering surface-mount parts, I strongly recommend a good temperature-controlled soldering iron such as a Hakko FX-888, paste flux, and quality leaded solder from a brand like Kester or MG Chemical. You can use lead-free solder, but I haven't.
If you have built your own Leako and tested it with a game that's not listed here, please submit a pull request to add it to this list.
| Game | Works? | Notes |
|---|---|---|
| Donkey Kong | Yes | |
| Zaxxon | Yes | |
| Time Pilot | Yes | |
| Carnival | Yes | |
| Frenzy | Yes | |
| Ken Uston's Black Jack / Poker | Yes | |
| Looping | Yes | |
| Omega Race | Yes | Tested with Hand Controller |
| Peripheral | Works? | Notes |
|---|---|---|
| ColecoVision controller | Yes | |
| ADAM controller | Yes | |
| Super Action Controller | Yes | Tested with Super Action Baseball only |
| Roller Controller | Partial | Tested with Slither only; my controller is not working properly, even on a real ColecoVision |
| Expansion Module #2 (steering controller) | Partial | Tested with Turbo only; my controller is not working properly, even on a real ColecoVision |
The latter two will be re-investigated as the controllers are tested, and hopefully this table will be updated with some better news in the future.
Please note:
- The Leako board does not have a ColecoVision expansion connector, so it cannot work with any Expansion Modules, including the ADAM.
- The Leako board does not have a ColecoVision power connector, so the Roller Controller will need to be powered independently using a ColecoVision power supply such as the ColUSB, or wired for a +5V source such as a USB cable.
If you power the Leako off a monitor or television set that is also being used to display the Leako, it can complete the "ground" circuit from the USB jack through the composite video jack and keep the Leako turned on, bypassing the power switch entirely. In this scenario, the Leako will remain powered on, regardless of the power switch position.
To work around this problem, try powering the Leako from a different USB power source, or use a television that isolates USB ground from video ground.
Thank you to Cheshire Noir and Tom Storey for figuring this one out.
More small fixes.
- Move U20/U11 to other side of board so cartridges with extra long skirts or loose PCBs won't interfere with them.
- Move mounting hole added in previous step to side of cartridge slot, so you don't have to use a low-profile screw head there anymore.
- Larger pads on the 74LS574s, to ease soldering.
- It is now much harder to hit the video filtering capacitor with the tip of a video cable.
- Upgraded project files to KiCad 6
Many small fixes, mostly around reliability.
- Correct missing junction from D3/D4 to R35 (EXT_QUAD pulldown.) Thank you to Oliver Fiero for catching this.
- Unused logic inputs grounded to reduce power consumption.
- Change controller ports from generic KiCad DE9 footprint to AE10968-ND
- Change -5V charge pump because of parts shortage. Now ICL7660.
- Controller port numbers on schematic now reflect actual logical controller ports.
- Barrel jack 5V replaced with USB-B to broaden availability of high-quality regulated power supplies.
- Additional mounting hole behind cartridge to reduce amount of board flex when cartridges are inserted and removed.
- Thicker power traces.
- Passives now labeled on board where possible, to speed assembly.
First working version.