A friend made an 8 bit cover of the iconic Nine Inch Nails album 'Pretty Hate Machine' which is appropriately named 'Pretty Eight Machine'. It's an awesome cover of the entire album and as mentioned is done entirely on eight bit architecture digital sound chips. If you're a NIN fan I would strongly suggest taking a listen on Spotify and if you like it then buy it. Here's where you can find it:

Spotify:

https://play.spotify.com/album/3l2Q4eTx2BT0BbH3GcFAGP?play=true&utm_source=open.spotify.com&utm_medium=open

Google Play Store:

https://play.google.com/store/music/album/Inverse_Phase_Pretty_Eight_Machine_Special_Edition?id=Brotdduonrt7hp7eoyue657kfey

iTunes:

https://itunes.apple.com/us/album/pretty-eight-machine-special/id889468022

Loudr:

http://loudr.fm/release/pretty-eight-machine-special-edition/pypns

Bandcamp:

http://inversephase.bandcamp.com/album/pretty-eight-machine-se