The Amstrad CPC 6128 was the successor to the Amstrad CPC 664 which had a very short life. It had almost all the same features as the 664, except the memory. Like the 664, only 42 Kb could be accessed, the upper 64 Kb were used as a RAM disk or to store data. It was sold with quite a good quality monitor (monochrome green or color) and a built-in 3" floppy disk drive (2 x 180 KB).
It ran under Amsdos (the Amstrad Operating System) or under CP/M 2.2 or CP/M 3.0 (CP/M +). The CP/M 2.2 OS was bundled with DR Logo and CP/M+ with GSX (the graphic extension of CP/M). Like the CPC 664, the Amstrad CPC 6128 was almost fully compatible with the CPC 464.
The German version of the Amstrad (Schneider CPC 6128) had different "real" connectors instead of main board edge connectors. Norbert Unterberg reports that the main reason for this was that the original Amstrad did not pass the German "FCC" test because it was polluting its surroundings with electromagnetic waves, and the rules for that were much stricter in Germany. That's why the Schneider got real connectors and a metal housing inside.
However, after "Schneider Rundfunkwerke" stopped selling the Amstrad CPC series of home computers and the PCW series of word-processors, Amstrad continued to sell the CPC under the Amstrad brand name in Germany.