In that 5th gen list, I think I may have left out a few others as well (like the Sanyo and Goldstar versions of 3DO, as pointed out before).
By the way, a few of the consoles you listed are not actually 2nd gen... The Pong & Odyssey clones are 1st gen, while the Sega SG-1000 and Telegames Personal Arcade are 3rd gen.
The thing about the 2nd gen itself, however, is that it was more like two completely seperate console wars:
"Gen 2.0" War (all released during 1977-1979)
- Fairchild Channel F
- Atari 2600
- Bally Astrocade
- RCA Studio II
- Magnavox Odyssey 2
"Gen 2.5" War (all released in 1982)
- Arcadia 2001
- Atari 5200
As you can see, there is a fairly big gap between the "Gen 2.0" war and the "Gen 2.5" war, so I wouldn't really consider them to be part of the same continuous console war, as was the case with the 5th gen (where there was a continuous stream of consoles released from 1993 to 1996).
Except there's no such thing as a 2.5 gen, you just completely made that up. A lot of those "gen 2.0" systems as you called them, were still being produced and new games still being made for them. So they were still in the same generation. Heck, during that entire era, Atari 2600 was doing the best out of all of those system sales-wise and number of games released.
BTW, the Sega SG-1000 is a 2nd gen console, the Master System (or Sega Mark III in Japan) was Sega's 3rd gen system. The Telegames Personal Arcade is definetly a 2nd Gen system too, it plays ColecoVision and SG-1000 games, it doesn't have original games.
As for the 1st gen system, yeah, most of those are 1st gen systems. But many electronics and toy companies continued to make them far into the 2nd generation, as well, which is why I included them. The whole point of this was talking about how crowded some generations were.
I don't mean to go off-topic, but...
I didn't make anything up other than maybe the name "Gen 2.5"... In 1982, the ColecoVision, Atari 5200, Arcadia 2001 and Vectrex were all marketed as "next generation" consoles, but that attempt at starting a next generation was cut short by the 1983-1984 crash. It seems clear to me that there is a forgotten "crash" generation that we're missing here.
By the way, according to your own reasoning, if the SMS is the next gen after the SG-1000... then wouldn't that make the Atari 5200 next gen after the 2600? If anything, the gap between the 2600 and 5200 (five years) is much wider than the gap between the SG-1000 and SMS (two years). But the reason why I said SG-1000 is 3rd gen (despite being a gimped ColecoVision) is because its main competitor was the NES (they were both released on the same day), not the previous 2nd gen consoles. Also, the SG-1000 and NES were both more or less seen as "2nd gen" consoles in Japan (which was a bit late to the console game), so that also kind of messes things up a bit. But the point is that the SG-1000 was part of the NES console war, not the Atari 2600/5200 war (due to different geographic locations).
And finally, I'm well aware the 2nd gen was one of the most overcrowded console wars, along with the 5th. But to me, it just feels like two seperate console wars, since the ColecoVision's main competitor was the 5200, not the 2600... In fact, the ColecoVision even had an official add-on that could play 2600 games! It would be like saying the Dreamcast as a 5th gen console just because it was around at the same time as the PS1 and N64. Anyway, I'm not trying to say we should re-categorize the generations, but I think it's important to recognize that there was a separate "Gen 2.5" of some kind (which the SG-1000 might also belong to).
Yeah, you made that up. It's obvious you put a lot of thought into it, but you did make it up. Nowhere else in all my years of gaming have I seen a "2.5" gaming generation. Generations have been clearly defined in a number of books, magazines, and websites for years.
Here's a list to explain things to you, which includes the SG-1000 in the 2nd Generation: