Ford Motor Company Limited

Richard A Pidsosny

Michael J Burke

Frederick James Porter

Gerald J Lehner

John C Zimmer

Mark W Jarvis

An apparatus for replacing an undesired code stored in a plurality of storage locations in read-only memory (ROM) with a replacement code. The replacement code, including a jump-back instruction to readdress the ROM, are programmed into an EEPROM. First and second storage locations store the beginning address of the undesired code and the beginning address of the replacement code, respectively. When the beginning address of the undesired code is generated by a program counter, a comparator generates a transfer signal. In response, the beginning address of the replacement code stored in the second storage location is transferred into the program counter. Each address of the replacement code is then sequenced by the program counter until a central processing unit recognizes the jump-back instruction. The central processing unit then readdresses the ROM in response to the jump-back instruction after the entire replacement code has been executed in place of the undesired code.

Apparatus and method for correcting microcomputer software errors

A system in which several colors of the spectrum are selectable to be displayed having common polarity and with high contrast against a black background, utilizing liquid crystal cells along with linear and color polarizers disposed along an optical axis so that comparable results in either reflective or transmissive modes are achieved, with appropriate light sources.

Color selectable liquid crystal display system

A system for measuring distance traveled by a vehicle periodically updates the accumulated measurements, displays the updated measurements and electronically stores corresponding accumulations of updated distance data in a non-volatile memory device. The system employs a method of reading through the sequentially ordered storage locations of the non-volatile memory to determine the most recently stored correct data value as a value to be both displayed and used as a base value for subsequent measured distance accumulation.

Electronic odometer

A bi-directional interface circuit which functions as an output driver to drive a corresponding communication data bus in response to the output of an associated microcomputer and as an input buffer to communicate data from the associated data bus to the microcomputer, wherein such input and output data to and from the microcomputer is communicated to a single port on the microcomputer. The bi-directional interface circuit is controlled by sensing the impedance condition existing on the input/output port of the microcomputer and correspondingly switches to either its output driver mode or input buffer mode.

Bi-directional data transfer circuit that is directionally responsive to

A warning circuit particularly suited for indicating that an intermittently operated device has been operated for a predetermined cumulative length of time. The circuit utilizes a coulometer as a current integrator that accumulates the intermittent periods of time during which the device operates. At the end of the predetermined cumulative length of time, the impedance of the coulometer changes from a low level to a relative higher level. This change in impedance renders a first transistor conductive and results in a warning indication. A second transistor is latched into a state of conductivity that causes a feedback current to flow through the coulometer to maintain it in its high impedance condition. The warning indication is controlled by an amplifier circuit which, in turn, is controlled by the second transistor. Once the high impedance of the coulometer is achieved, the second transistor at all times retains its state of conductivity indicative of this condition, but the amplifier circuit is operative only when the intermittently operated device is in operation.

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Canton, MI, United States of America

Richard A Pidsosny