|Language||Commodore BASIC 7.0|
|CPU||MOS Technology 8502 + Zilog Z80|
|Speed||MOS 8502: 2 MHz (1 MHz for C64), Z80: 4 MHz (practically 2 MHz)|
|RAM||128 KB (64 KB for C64 mode)|
|Text modes||C64 and 128 mode: 40×25, 16 colors, 128 mode only: 80×25 or 80x50, 16 colors|
|Graphic modes||160×200, 320×200, 8 hardware sprites|
|Sound||3 channels, 6 octaves|
The Commodore 128D was released in the fall of 1985 in Europe. The US release date was in the summer of 1986. It was an updated version of the C128 with a detached keyboard and a 1571 disk drive in the same box as the main system unit, providing a sleeker, more professional-looking appearance, much like that of a desktop PC. In Europe the first C128Ds came in a plastic case with a side-mounted carrying handle and were technically exactly the same as a C128 with the 1571 disk drive. Additionally these models were equipped with a somewhat noisy cooling fan, leading to the model sometimes being referred to as the "128 Diesel".
Later models of the C128D came in a metal case; among these were the Commodore 128DCR (CR = cost reduced), which was widely sold in Canada and the USA. These later models had some minor improvements. The internal design was more integrated to save production costs, but also improved the thermal design, so that a fan was supposedly not needed anymore (later experience proved that the fan was a worthwhile addition and many C128Ds were so modified).
Inside, the C128D ROMs contained several bug fixes, and the 8563 VDC chip (in the C128DCR, the 8568) was equipped with the maximum capacity 64 KB of video RAM – four times that of the original C128. This permitted the C128D to do higher-resolution graphics with more colors in RGB mode, although very little software took advantage of this. With or without the extra RAM, the VDC's high-resolution graphics modes were inaccessible from the C128's BASIC. They could only be utilized by calls to screen editor ROM primitives (or their assembly language equivalents), or via third-party BASIC language extensions. The most popular such toolkit was Free Spirit Software's "BASIC 8", which added high-resolution VDC graphics commands to CBM BASIC. BASIC 8 was available on two disks (editor disk and runtime disk) and with a ROM chip for installation in the C128's internal Function ROM socket.