If you own a PC you can reliably emulate the Atari 2600 and in fact all reasonably well known 8 and 16 bit computers and consoles. It's debatable whether downloading the games themselves is legal however unless you own the original even though they're readily available all over the Internet. Many will say they're
abandonware which means they're so old that the developers don't care about their copyright any more for personal use, but technically it is still piracy if you don't own the original if they wanted to make a point of it so please be advised. You can also use an
open source DOS emulator called
DOSBox that allows you to run old DOS games on a modern PC.
I agree that some of the older games were excellent and more playable than a lot of games today even though the graphics are obviously very dated. Even some younger people are starting to appreciate play-ability over high end graphics however with an influx of indie retro style games on the market, some have become very popular.
Feh, I've never cared about the screwball legality of roms. Something that rom-users learned very quickly: nobody gives a crap about it. Even Nintendo, one of the most annoyingly strict companies, the most they ever do is that on very rare occaisions they might contact some rom-hosting site and demand that a couple of really super specific roms be taken down. Not ALL of the roms. Just like... 3. Mario, Zelda, and Metroid usually. They dont seem to care whatsoever about any others, which doesnt make sense to me, but whatever.
I suspect the reason is simple: Nobody makes money off of these old things anymore so they simply dont care. It'd be too much trouble and expense for them to actually DO much about it (not to mention that actions like that REALLY irritate the hell out of consumers, which obviously is best avoided when possible). Even Nintendo's Virtual Console is falling apart... heck, the Switch doesnt even have it.
As it is, I've already got 9000 arcade roms and 700 or so NES roms and also some 2600 ones buried somewhere, so... yeah, I"ve never been too bothered by that. Though when it comes to the 2600 I really prefer using the original cartridges. There's something special about that old machine. Plus the things are littered around my room anyway for no apparent reason... really, cartridges everywhere.
DOSBox I've used but it's often a bit beyond my patience. Well... beyond my patience to find the freaking games. Though I did play through Arctic Adventure recently, an ancient CGA game from the days when colors were a very limited resource. You got exactly 4 of them and that was it. I still remember the 3 most common color schemes even after all these years.
And yeah, those older games were often just great. And when I compare them to today's "main" stuff, well, the modern ones honestly hold up very badly, at least to me. The major companies have all become hyper-greedy, the quality of games has hit rock bottom (but OMG TEH GRAPHIX, sigh...) and I stopped buying AAA crap a long while ago. I stick almost entirely with indie stuff and retro games nowadays. I prefer my games to NOT suck, and also not be full of lootboxes or other horrid schemes.