Commodore 64
The Commodore 64 is an 8-bit home computer developed by Commodore and released in 1982 in both the US and Europe. While it enjoyed only moderate success in the US thanks to the rise of PCs and home consoles, it was a large hit in Europe thanks to the hardware scrolling and the SID chip used for sound.
There are variations of the C64 but they were not successful. Commodore 128 was an upgraded version with extra memory, more colors and an extra processor however only a few games took advantage of the features. There is also a console version called the Commodore 64 GS (basically the C64 without the keyboard) however it failed due to the expensive cartridge format and a limited library, some that forgot that it had no keyboard and could not be run. Also there were plans for an upgraded version of the home computer called the Commodore 65 however only a few units were made and was not released.
Ripping Tools
C64 Sprite / CharSet Ripper
Sprites from C64 games can be ripped using savestates from CCS64 or VICE making it easier to sprite rip. There are some games that use layers making it harder to rip such as Target Renegade and Crystal Kingdom Dizzy.
Suggested Emulators
VICE
VICE is a cycle accurate emulator for the C64 and the C128 but also has a less accurate version for lower powered computers or if the cycle accurate option doesn't run full speed on your computer. It is not easy to set up as well as changing the settings every time you boot the emulator up and the Auto Load function may vary depending on game.
CCS64
CCS64 also is an accurate emulator, featuring emulator speed modification, pausing, frame-by-frame animation, and save states. It is also shareware so it may require registeration and the developer may charge for the emulator in the future.