The Memotron 256 is a 256KB memory expansion for Amstrad CPC 464 computers made with period-correct components and design.

It will provide the same compatibility as the 1986 DK'Tronics 256KB memory expansion it is derived from. Will work in games, BASIC and CP/M 2.2, so you will be able to play the 128KB versions of CPC games as well as the few programs that make use of the full 256KB like Chibiakumas 2. It is compatible with the DK'Tronics bank switching software.

Each unit has been tested over at least 100 iterations of the dry-run test of the Amstrad Diagnostics V1.3A application https://github.com/llopis/amstrad-diagnostics

The PCB is made with high-quality ENIG gold surface finish and a chamfered edge connector for the additional expansion. The fabrication quality of the PCB is abysmally better than on the original DK'Tronics modules. All the ICs are mounted over sockets for easy future maintenance.

It can be configured with jumpers to work as a 256KB or as a 64KB expansion. By default the 256KB of memory will be mapped to banks 0-3, unless you enable the "silicon disk" onboard jumper that like in the original will map the memory to banks 4-7. So you can plug two modules for a total 512KB of memory expansion. With one module you will have on the CPC 464 64KB onboard plus 256KB on the expansion for a total of 320KB available.

The module includes a sturdy 3D-printed case that will fit perfectly the CPC 464 expansion port profile. The expansion will take more space on the desk than the original as on the original the connectors are perpendicular to the board while on the Memotron they are on the same plane to make the assembly process easier.

The original DK'Tronics expansion for the CPC 464 do not fit well the CPC 6128 profile but the Memotron case legs can be removed to make it fit a 6128, although it is not fully compatible with the 6128 (expect it to work in games and Basic but not on CP/M plus). Note that the german Schneider 6128 doesn't have edge connectors for expansion but centronics-type ones so the expansion won't fit at all on a Schneider 6128.

All the details about the Memotron as well as the design files can be obtained from my Github: https://github.com/inmbolmie/Memotron

There are other convenient alternatives available for CPC memory expansions, but I wanted to make something with a period-correct look and feel and that could be made and assembled by anyone.