Control system to control operation of an apparatus, more particularly operation of an automotive vehicle

A vehicular microcomputer system, to control operation of an internal combustion engine and additional vehicular apparatus, having

• a central processing unit (30);
• an interface (20);
• means (10) to apply apparatus operating data to the interface (20);
• read-only memory (40);
• a buffer random-access (RAM) memory (50);
• an interconnection bus (80) interconnecting the central processing unit (30), the interface (20), the read-only memory (40) and the buffer memory (RAM) (50);
• an auxiliary read-only memory (41) selectively connectable to said interconnection bus (80);
• and means (11) coupled to the central processing unit (30) to recognize whether or not the auxiliary read-only memory (41) is connected to the bus (80),
• and comprising, in accordance with the invention,
• means for controlling the operation of the program of the central processing unit (30) including
• program data (91-94) stored in modular or block form in the read-only memory (40) and auxiliary program data (95-98) stored in modular or block form in the auxiliary read-out memory (41);
• the program data stored in the read-only memory (40) including
• a basic organization program (93),
• a program step (91) for recognition of the presence of the auxiliary read-only memory (41);
• and
• a conditional instruction that, whenever the presence of the auxiliary read-only memory (41) is recognized, the central processing unit (30) is to execute selected instructions or program steps (92, 96,97) from the read-only memory (40) and the auxiliary read-only memory (41) according to a program sequence (95), in the auxiliary memory (41), alternative to, and to the extent necessary, inverted with respect to, the sequence in said basic organization program (93).