Abstract: A microprocessor based apparatus for use as a bus controller and as a remote terminal in a time-division multiplex serial data bus system. The apparatus comprises a single chip which, in a preferred embodiment, is in the form of radiation hardened LSI/CMOS/SOS. It operates on a one bit per instruction basis and includes program control of output signals and word length. The described embodiment is program adapted to satisfy the performance requirements of the applicable military standard, but is easily modified, by changing the contents of an external expandable instruction storage device, to accommodate alternative requirements such as different word lengths, different message formats, and even different bus protocols. A data format encoder and data format decoder provide means to convert from Manchester bi-phase data to NRZ data for receiving data from the data bus and to make the opposite conversion for transmitting data over the data bus.

Abstract: An apparatus and method for predicting the time occurrence of the desired angular position of a rotating body, such as the crankshaft of an internal combustion engine. The apparatus includes means for storing a nonlinearly changing count that is set to a known starting value when the rotating body is at a known angular position. A computing means is included for computing the value of the count that corresponds to the time when the rotating body will be at the desired angular position. The computation is achieved by extrapolating from known count information based upon prior periods of angular displacement of the rotating body during periods of known duration.

Abstract: A multiplier for multiplying a fixed point multiplicand by a floating point multiplier utilizes decode logic which provides control signals related to two numbers, the sum of which is approximately equal to the mantissa of the multiplier. The multiplicand is separately left shifted in two circuits, responsive to the control signals, by a number of places respectively corresponding to the values of said two numbers. The shift circuit outputs are summed algebraically in an adder. The sum is then shifted by a number of places and in a direction determined respectively by the magnitude and sign of the power of the floating point multiplier. The result is a close approximation of the desired multiplication product. The multiplier advantageously is employed in an electronic musical instrument.

Abstract: In this key switch scanning and encoding system, open (OFF) switches may be scanned at a faster rate than closed (ON) switches, and a coded signal is produced indicative of each closed switch. The switches are arranged in a matrix of M groups each connected to N common output lines. The switch groups are enabled sequentially, one at a time. As each group of switches is enabled, the N output lines sequentially are gated to a coding matrix. If the gated line is associated with a closed switch in the enabled group, an output code is produced by the code matrix, which, together with a signal designating the enabled group, uniquely identifies the closed switch. Scanning is delayed briefly to permit utilization of the encoded output. If an open (OFF) switch is scanned, no code is produced by the code matrix. This no-code condition immediately causes the next switch matrix output line to be gated to the code matrix. In this way, open switches are "skipped over" or scanned at a rapid rate.