Internal 512 KB RAM expansion for CPC6128 from german magazine '''c't, issue 10/1987''' [other source says 11/87]. The DIY project name is '''CPC 6512'''.
One half (256K) of the total (512K) expansion memory can be accessed as Video RAM (with normal expansions, only 64 KB are accessible as Video RAM). The c't expansion is compatible with [[Standard Memory Expansions]], and provides the additional CRTC feature, but it misses 64 KB usually addressed via I/O ports &7FFC, &7FFD, &7FFE and &7FFF.