The Commodore 128 is the successor to the Commodore 64, the best-selling home computer ever. The Commodore 128 has also broken sales records, but not on the scale that the Commodore 64 has managed to achieve.
The Commodore 128 was launched in 1985 at a computer show in Las Vegas, where it was launched as the major competitor to the Apple Macintosh and the IBM PC. The accompanying advertising slogan was therefore "Bad news for Apple and IBM".
The Commodore 128 (or C128) was designed to be fully backwards compatible with the Commodore 64. The C128 could work in 3 modes: as a full C64, as a 'native' C128 with 128 kilobytes of memory and as a CP / M machine.
The C128 gained some popularity because it could run C64 programs while also using business software, but was quickly overtaken technically by competitors such as the Atari ST.