The Commodore 128 (C128, CBM 128, C=128) home/personal computer was the last 8-bit machine which was commercially released by Commodore Business Machines (CBM). Introduced in January of 1985 at the CES in Las Vegas, it appeared three years after its predecessor, the bestselling Commodore 64. The primary hardware designer of the C128 was Bil Herd.
The C128 was a significantly expanded successor to the C64 and unlike the earlier Plus/4 it remained compatible. The new machine featured 128 KB of RAM (externally expandable to 640 KB) and an 80-column RGB monitor output (driven by the 8563 VDC chip with 16 KB dedicated video RAM, although following the release of the 128D later "flat" 128s had 64 KB of VRAM), as well as a redesigned case/keyboard with a numeric keypad.
- CPU: MOS Technology 8502 @ 2 MHz (1 MHz selectable for C64 compatibility mode)
- Zilog Z80 @ 4 MHz (effectively running at 2 MHz due to stopping half the time to allow VIC-II video chip access to system bus)
- RAM: 128 KB system RAM, 2 KB 4-bit dedicated color RAM (for the VIC-II E), 16 KB or 64 KB dedicated video RAM (for the VDC)
- Up to 512 KB REU expansion RAM
- ROM: 72 KB (28 KB BASIC 7.0, 4 KB MLM, 8 KB C128 KERNAL, 4 KB screen editor, 4 KB Z80 BIOS, ca. 9 KB C64 BASIC 2.0, ca. 7 KB C64 KERNAL, 4 KB C64 (or international) character generator, 4 KB C128 (or national) character generator) � expandable by 32 KB Internal Function ROM (optional; for placement in motherboard socket) and/or 32KB External Function ROM (optional; for placement in REU socket)
- MOS 8564/8566 VIC-II E (NTSC/PAL) for 40-column composite video
- MOS 8563 VDC (or, in C128DCR, the 8568) for 80-column digital RGBI component video, compatible with IBM PC CGA monitors, monochrome display also possible on composite
- MOS 6581 SID (or, in the C128DCR, the MOS 8580 SID) synthesizer chip