A modular computer system having an integral electronic bus includes a number of computer components each housed in a casing. Each casing includes a standardized male connector extending from the front surface of the casing and a female receptacle, which is compatible with the male electrical connector, extending into the casing from its rear surface. Each connector and receptacle includes an array of electrical contacts disposed in a predetermined arrangement, such that each connector contact is aligned with a corresponding contact of the casing receptacle. Corresponding pairs of connector and receptacle contacts mate to form the integral electronic bus. Any combination or arrangements of computer components may be electrically interconnected by engaging the receptacle of each casing with the connector of an adjacent casing, thereby forming the integral electrical bus between the interconnected modules.