Separated at birth? SEGA SG-1000 & ColecoVision

[Neb6]

Okay, I'm on a CV/SG-1000 research kick today.

Something that is making me say "Hmmm..." is the question of which was developed first, the ColecoVision or the SG-1000. AFAIK the internals are the same for both machines. Same CPU, same GPU, same audio chip.

Here's an article on the SG-1000. It says that it was test marketed in 1981:
http://www.old-computers.com/museum/computer.asp?c=1257&st=2

If that's true, then it puts the SG-1000 out there a year before the ColecoVision.

However this article says that the designer of the ColecoVision started working on it in 1979:
http://www.racketboy.com/retro/colecovision-a-beginners-guide

So that puts the ColecoVision first.

Is anyone aware of the details? I'm thinking someone copied someone.

[Greg2600]

I wouldn't say anyone copied anyone else. The Colecovision, SG-1000, and MSX all used the same CPU and Graphics processor. They were off the shelf, common chips. The system bios was obvious different between them.

[Alpha2099]

It's hard to determine if either company copied from the other one. Don't forget, the SG-1000 never made it to the U.S. It was only sold in Japan, New Zealand, and Australia. The ColecoVision was only found in U.S. and European markets, so it looks like they each kept to their own corners. Yes, they do have similarities, but I think that speaks more to the available technology of the early 80s allowing for these types of systems.

[ccovell]

For similarities, look into the history of TI's TMS9918 chip: http://en.wikipedia.org/wiki/Texas_Instruments_TMS9918

The Z-80 CPU was also very common among early-80s computers and game systems.

[Steve W]

I'd have to say that what inspired the MSX line of computers would be the SpectraVideo computers that came and went in the US without anybody noticing. The Z80 and TMS9918A were both extremely powerful chips that were also not tremendously expensive, and so therefore were a good foundation for a computer line. And you read right, the Colecovision was on the drawing board quite possibly from 1979 but they didn't bring it to market until the costs of the components dropped to an acceptable level. The hardware designer of the Colecovision also claims he had something to do with the General Instruments design that Coleco passed on but was picked up by Mattel to become the Intellivision.

[blue lander]

The Tomy Tutor uses a similar architecture too. There's only so many ways you can build a computer or game system out of these chips, so it's no suprise they're all so similar. Microchip companies also usually publish datasheets with schematics of "example circuits" showing how to build a circuit around their microchips, I bet most companies just copied that.

[goldenband]

Here's an article on the SG-1000. It says that it was test marketed in 1981:
http://www.old-computers.com/museum/computer.asp?c=1257&st=2

If that's true, then it puts the SG-1000 out there a year before the ColecoVision.

I asked about this at SMSPower (http://www.smspower.org/forums/viewtopic.php?t=9716) a while back. My own suspicion is that it's a bogus claim, but of course I'd welcome hard evidence of a test market.