The Ford EEC or Electronic Engine Control is a series of ECU (or Engine Control Unit) that was designed and built by Ford Motor Company. The first system, EEC I, used processors and components developed by Toshiba in 1973. It began production in 1974, and went into mass production in 1975. It subsequently went through several model iterations. EEC I and II The EEC I and EEC II modules used a common processor and memory so they can be described together. The microprocessor was a 12-bit central processing unit manufactured by Toshiba, the TLCS-12, which began development in 1971 and was completed in 1973. It was a 32mm² chip with about 2,800 silicon gates, manufactured on a 6 µm process. The system's semiconductor memory included 512-bit RAM, 2kb ROM and 2kb EPROM. The system began production in 1974, and went into mass production in 1975. EEC-III This system was used on certain 1981-83 vehicles. There were two different EEC-III modules; one for use with a feedback carburetor, and one for use with Ford's "Central" throttle-body fuel injection system. The module size and shape were approximately the same as the EEC-II and still utilized the external memory module. The two modules had differently keyed connectors to prevent accidental insertion in the wrong vehicle. EEC-III uses a Duraspark III module (brown grommet where wires emerge) and a Duraspark II ignition coil. A resistance wire is used in the primary circuit. The distributors in EEC-III (and later) systems eliminate conventional mechanical and vacuum advance mechanisms. All timing is controlled by the engine computer, which is capable of firing the spark plug at any point within a 50-degree range depending on calibration. This increased spark capability requires greater separation of adjacent distributor cap electrodes to prevent cross-fire, resulting in a large-diameter distributor cap. EEC-III on carbureted cars controlled the same Ford 7200 VV carburetor as the EEC-II. On fuel-injected cars, the module fired two high pressure (approximately 40 psi) fuel injectors that were mounted in a throttle body attached to a traditional intake manifold in the center valley of the 5.0 liter (302 cid) engine. The processor was designed and manufactured by Motorola. It featured an 8-bit data length, a 10-bit instruction length and a 13-bit address length. The address space was "paged", meaning you could not directly address all of the address space without special instructions. There were 4 pages. Page 0 was