Stumbled on this interesting blog which has some great sample packs of 8 bit bleeps and tones, taken from many well known electronic devices. The featured soundset, is a copyright-free and license-free pack of the Phillips SAA-1099 sound chip. The soundset contains 96 samples that are pitched, and 16 samples of noise from varying frequencies. All the sounds come from hardware with no filtering or additional processing. There are also  other free sample packs available such as :
Ukulele
Commodore 64 SID 8580
Yamaha YM2413 pitched and drum
Yamaha YM2413 drums
SEGA Master System II SN76489
SEGA Mega Drive YM2612
Khene
General Instruments SP0256-AL2
Atari POKEY Noise
Atari 2600 TIA
These sounds would be great for drum and bass, dubstep, grime, hip hop, industrial, ambient and more so head on over there and check them out!
