The Commodore 128 is the last 8-bit platform released by Commodore.
It supports up to 1 MB RAM, double CPU speed (during screen blanks), a PC Boot Loader equivalent, international keyboards, an additional 80-column display, an alternative Z80 CPU, and much stronger development facilities.
Although the C128 sold millions, little was actually produced for it.
When you turn the computer on, it accesses the inserted disk. If it finds a boot loader (on the first sector), the game automatically starts. Otherwise, Commodore BASIC V7.0 starts.
Before loading native Commodore 64 games, you must switch your C128 into C64 mode. A few detect the C128 anyway and use its extra RAM and speed.
Like earlier computers, the C128 is built into the keyboard, and a separate disk drive must be explicitly connected.
Like upcoming computers, the C128D has a built-in 5'25" disk drive and external keyboard.
Labelled C 128 DCR inside, the cost-reduced C128D got the 8580 sound chip and more 80-column RAM. Its earliest known mention is 1988.
Music and Sound
The audio hardware has not changed from the Commodore 64, except that games like Frantic Freddie (C64) and Blue Angel 69 (C64) are completely mute. This is because they access the SID chip through non-standard ports (most likely as a rip protection) that got official (non-audio) purposes on the C128.
The computer's built-in Commodore BASIC V7.0 adds six sound-related commands that grant access to almost all hardware features and even pitch sweeps: VOL, SOUND, ENVELOPE, FILTER, TEMPO, and PLAY. The last uses a language.