>I'm not going to dive into a history lesson here, but the Arcadia 2001 was developed by Universal Appliances Limited (UAL) out of Hong Kong and released under license in the US market by Emerson in May 1982 (more details on this here). It was only produced for about 1.5 years in the US. There are 22 confirmed US releases but due to UAL having issued many licenses for related systems (more than 30!) around the world, that number increases to around 50 or so.
Actually, I'm not sure if there was any licencing required, as far as the hardware is concerned. There is no BIOS, and the chips are standard off-the-shelf components available for any company to purchase directly from Signetics, and the motherboard is basically the Signetics reference design. This may in part explain why there was such a proliferation of these machines from such a variety of manufacturers. The software is a different matter of course.
>What has always befuddled me is why every sound that comes out of the system brings to mind the sounds of an animal in its death throes. I mean, the sound chip clearly had as much range as the primitive chips on my Odyssey 2 and Apple II, but while the sounds on the former were boring and the latter a bit scratchy, nothing this side of Tom Waits sounds as bad as an Arcadia 2001. Was there a technical reason for that?
It's just an ordinary square wave generator, but there are restrictions in the choice of frequency, especially for higher notes. So music will sound out of tune.
Specifically, only pitches that are divisors of 7874 Hz can be produced. The emulator has an option to force tones to the nearest equivalent on the even-tempered musical scale, which makes music sound better.