How many game systems are truly backwards compatible?

Video Games
1

As far as I can figure, the following game consoles are backwards compatible:

  • Sega SG1000 Mark III/Master System (compatible with SG1000 cartridges)
  • Atari 7800 (Compatible with 2600 cartridges)
  • Sega Mega Drive/Genesis (requires pin adapter to play Master System cartridges)
  • Sega Game Gear (requires pin adapter to play Master System cartridges)
  • Game Boy Color (compatible with original Game Boy cartridges)
  • Game Boy Advance (compatible with original Game Boy and Game Boy Color cartridges)
  • Neo Geo Pocket Color (compatible with original Neo Geo Pocket cartridges)
  • WonderSwan Color (compatible with original WonderSwan cartridges)
  • PS2 (compatible with PS1 discs)
  • DS (compatible with GBA)
  • Xbox 360 (limited compatible library of original Xbox discs)
  • PS3 (compatible with PS1 discs, limited models compatible with PS2 discs)
  • Wii (compatible with GameCube discs)
  • 3DS (compatible with DS cartridges)
  • Vita (compatible with digital purchases from the PSP store previously purchased on PSP)
  • Wii U (compatible with Wii discs)
  • Xbox One (limited compatibility with Xbox and Xbox 360 discs, cannot read games from discs, requires digital download)
  • PS5 (compatible with PS4)
  • Xbox Series X/S (compatible with Xbox One discs [many games require a digital download], same limited library of Xbox and 360 games as Xbox One)
  • Nintendo Switch 2 (Compatible with Nintendo Switch in some yet to be announced way)

All other systems people consider backwards compatible that I’ve found mention of require an add-on that essentially bolts another console on (for example, the Expansion Module #1 for the Colecovision and the VCS Cartridge Adapter for the Atari 5200 containing an entire Atari 2600, or the Super Game Boy containing an entire Game Boy).

Did I miss anything listing backwards compatible consoles?

2

It’s interesting to note which of these are hardware backward compatible (better) and those that rely on software emulation (worse)

3

Good point. The ones that rely on software emulation are:

  • PS2
  • Xbox 360 (and very limited library)
  • PS3 (Software for PS1, hardware for PS2 except some models which are software)
  • Vita
  • Xbox One (and very limited library)

The rest are hardware compatible.

4

Early PS2 were hardware backwards compatible. Except GPU was software emulated. Later revisions were all via software. It’s a blurry line there.

5

Huh, I never knew even the first PS2 emulated the PS1 GPU…

And the latter ones were completely software?

I’d have to say they did a pretty good job of it because I never noticed.

This means the PSP has more real PS1 backward compatibility than most PS2s, given it basically runs PS1 CPU code natively.

6

(There were even some GPU changes in later revisions of the PS1. Some games have graphical bugs.)

POPS is the PS1 on PS2 emulator, here’s a great article how it was created by one man: The Story of the PS2’s Backwards Compatibility From the Engineer Who Built It | by Tom James | Medium

7

Xbox One has a GPU emulator but the games themselves are recompiled for the host CPU, so all software. Just to add a note here.

8

To add to this, PSP is partial software emulation, for the graphics. Game logic and CPU instructions are handled on the CPU natively, but the graphics are emulated.

9

Wii U also runs GCN games if hacked.

Not sure if that counts for anything especially since I don’t think it reads GCN discs.

Also some late Wii systems don’t run GCN games and some late Genesis systems don’t run Master System games.DSi also removed the GBA slot.

1 Like
10

Yeah what’s funny is Wii U is hardware backward compatible with Gamecube, but can’t run the discs.

PS2 is at least partially (and as I have now learned sometimes totally) emulated, but is compatible with the media. Same with PS3 to PS1.

Which one is really backward compatible? On a computer level, it’s the Wii U really.

It’s so weird, Nintendo basically crippled the Wii U by making it have to have full hardware Wii compatibility requiring a very out of date Power PC set up. What a mess.

11

Same for the 3DS with the GBA.

12

I wonder if there’s a minor exception to 3DS being fully hardware compatible with GBA.

So GBA included the Game Boy’s audio hardware, the programmable sound generator, or PSG.

This PSG was used when playing GB/GBC colour games, of course, but developers had access to it for their GBA games. The GBA, lacking dedicated sound hardware, meant audio used CPU cycles, so some of the best GBA composers and audio programmers would rely on, or mix and match music from, the Game Boy’s PSG.

Early Konami games did this often, like Konami Krazy Racers or Yu-Gi-Oh Duel Monsters 5 and 6:

DS did include the GBA’s original sound system, so I’m guessing 3DS inherited that too?

Back on topic, how does a GBA game handle all of this? It doesn’t , Nintendo fitted a separate sound system (within the same enclosure) for GBA mode that includes its own channels and mixer that follows the specifications of the predecessor. This way, GBA games won’t be affected by the new mixer’s limitations. Unfortunately, since this subsystem is segregated from the DS one (in other words, it doesn’t output to the DS’s mixer), DS games aren’t able to use it

Source: Nintendo DS Architecture | A Practical Analysis

13

Should be fairly easy to test this. Just boot one of those games up on a 3DS and see if the sound is right.