This adapter is connected to expansion bus same as joysticks adapters, giving us the possibility of connecting an standard keyboard, type AT or PS/2. (Old keyboards 94-keys are unuseful). This heart of the adapter is a microcontroller PIC 16F84. This PIC should be programmed before insertion on the board ( a few steps forward will be explained how to program it). Once the PIC be programmed an inserted, is ready for working, and you don't need to open nor load anything in your Spectrum. .