Abstract: This invention relates to the recording and reproducing of digital data on magnetic tape and, more particularly, to increasing the effective data recording density via reducing the lengths of the interblock gaps. The tape is stopped and started with moderate accelerations, in distances which are generally greater than the interblock gap length. In a particular form of the invention, when the tape is to be stopped at the end of a data block, it is stopped in a distance greater than the gap length, reversed and brought to rest with the record/reproduce head on the interblock gap. When the tape is to be started, it is first reversed for a short distance, and then driven in the desired direction such that it is up to normal operating speed at the end of the interblock gap. The interblock gap length may be substantially shorter than the distance required to stop and start the tape. The effective data recording density is increased through this interblock gap length reduction.

Abstract: The subject invention relates to digital multimeter instruments for the measurement of physical quantities and, more particularly, to increasing the effective measurement resolution and accuracy thereof. In one form, a multirange digital voltmeter is provided with scales and ranges in a 1-2-5-10 relationship. The voltmeter includes an analog-to-digital converter which is connected through a digital multiplier to a digital display. The multiplier provides multiplication ratios of 1, 2 or 5, depending on the selected scale. The displayed value will change in increments of 1, 2 or 5 units of the least significant displayed digit for a change of one unit of the analog-to-digital converter output, depending on the selected scale and corresponding multiplier setting. This allows the various scales to have at least approximately the same number of digital steps over their full ranges.

Abstract: A system for the magnetic confinement of a plasma for purposes such as the facilitating of thermonuclear fusion reactions. In one form, the major confining field is generated such that in local regions the magnetic field intensity increases with increasing distance from the central part of the confinement space. This provides a strong confinement in those local regions. The currents generating the major confinement field are time varying such that the local strong confinement regions move relative to each other and pass through the entire confinement space. Thus, the plasma is generally pumped through local strong confinement regions, and all parts of the confinement space are periodically subjected to a strong confining field.

Abstract: This invention relates to analog-to-digital conversion systems, and makes use of the properties of cyclic variables such as phase angles. In one form of the invention, an analog signal to be converted into a digital value is applied to an input of a phase modulator. The phase modulator shifts the phase of an oscillator signal in accordance with the value of the analog input signal. A series of alternate frequency doubling and heterodyne frequency conversion steps are used to generate a series of signals with the same frequency as the oscillator output signal, but with phase shifts of 2, 4, 8, etc., times the phase shift of the phase modulator output signal. Binary (two-state) signals are generated whose values correspond to the relative phases of the phase modulator output and multiplied phase shift signals. The values of these binary signals are sampled when an analog-to-digital conversion is to be performed.