64 Kbyte Static Ram Extension For Msx Computers

14 EE September 1988 64 KBYTE STATIC RAM EXTENSION FOR MSX COMPUTERS Although the concept of MSX allows the addressing of up to 1 Mbyte of memory, the number of computers that use more than 128 Kbyte is surprisingly low, and ready-made RAM extension modules thin on the ground. We decided to do something about this, and developed a plug-in RAM extension that enables MSX users to increase the total available memory of the computer in steps of 32 or 64 Kbyte. With a mere 64 Kbyte installed as a stan- dard, and 128 Kbyte available on newer models only, MSX computers do not follow the trend towards the use of vast amounts of system memory. The diagram of Fig. 1 shows the theoretical memory structure of the MSX concept, which was originally designed for 1 Mbyte of addressable memory. In practice, however, there is not a single MSX computer that actually uses all of the available system memory. In principle, any MSX computer can have up to four so-called primary slots, which are, in turn...