Base unit for a keyboard, accessory module for a keyboard, and keyboard

A keyboard comprising:

• a base unit having a substantially rectangular layout, the base unit including
• an equipment portion, formed so that it can be equipped with a plurality of key switches for the keyboard, wherein the equipment portion is arranged on a first side of the base unit, and
• at least one coupling portion, wherein each coupling portion comprises a first coupling feature and a second coupling feature, wherein the first coupling feature is arranged on the first side of the base unit and the second coupling feature is arranged on a second side of the base unit facing away from the first side, wherein each coupling feature is formed along a longest side of the base unit between narrow sides of the base unit, the longest side of the base unit being parallel to a spacebar;
• and
• at least one accessory module, each accessory module mechanically coupled to a corresponding coupling portion of the base unit, each accessory module including a first mounting feature and a second mounting feature;
• wherein the first coupling feature of each coupling portion of the base unit is formed for positive locking with the first mounting feature of the corresponding accessory module;
• wherein the second coupling feature of each coupling portion of the base unit is formed for positive locking with the second mounting feature of the corresponding accessory module;
• and
• wherein the at least one accessory module is formed to clasp around the longest side of the base unit.