Previously charged surge tanks supply the initial charging gas for delivery tanks until a predetermined pressure between gas in the delivery tanks and the surge tanks is reached, at which point a compressor charges the delivery tanks. The surge tanks are themselves charged when the pressure in an outlet line from the compressor reaches a predetermined value.

Methods and apparatus are described which provide for granting access to a computer or other system to a plurality of users having different priorities. Each user is assigned to a priority group within which all users receive sequential access. Priority groups as a whole are granted access in accordance with their usage requirement and associated relative priorities. Each group is assured access for at least a minimum period within a longer reference period.

The invention comprises apparatus for assigning priority among several data channels being multiplexed into one data bus. Priority is based partly on recent usage history, and is increased for those channels having frequent recent use. Additionally, those channels which have requested, but have not received service are given continually increasing priority until service is granted.

There is disclosed a technique for interfacing various subscriber groups having different security levels which subscribers are associated with the same telephone system. According to this invention, every terminal element or subscriber has a programmable frame delay for the out and in registers associated with the switching network. In this manner, each subscriber of the same priority will receive the same delay on the transmit and receive paths. This delay is accommodated by means of an up or ...

In various types of systems it is expedient to have a plurality of control consoles, each assigned a relative priority so that they may control the associated equipment in a predetermined hierarchy. The priority wiring requires only a pair of wires from one console to the next. A higher priority console, when activated, disables all lower priority consoles in the hierarchy and an indicator at each disabled console is activated to indicate the disablement. The indicator at the active console is n...

An interrupt control unit which couples a plurality of peripheral devices to a central processor includes a counter for outputting signals for monitoring a plurality of encoders each coupled to a number of peripheral devices, each encoder outputting the address of a requesting peripheral device when enabled. A memory unit outputs the address of the highest priority peripheral device for each output signal of the counter and a comparator compares the address of the peripheral device having the hi...

A digital processor including both macro and micro instruction generators. The micro-instruction generator comprises a sequencer for generating instruction addresses, a memory for generating instructions in response to the addresses and a pipeline register adapted to receive the instructions for execution. The sequencer operates at a constant CLK 1 rate while the pipeline register operates at a variable CLK 2 rate; i.e., the occurrence of a branch instruction in the pipeline register operates to...

A priority gating system is disclosed which is useful with a communication subsystem having a multiplicity of parallel input/output lines. To service these lines a priority address determination is made for all channels with 0 designating the highest priority and (n-1), the lowest in an n-channel system. Each signal line to the input/output devices will have a card select buffer serially inserted therein. All of the buffers will be enabled during the data transfer portion of the cycle. At the en...

A high speed priority interrupt system which permits a microcomputer to service a plurality of peripheral units on a priority basis is provided. Interrupt address jump vectors corresponding to the routines for servicing the peripheral devices are stored in a read only memory and are selectively transferred to a program counter in accordance with a predetermined priority basis to allow the microcomputer to interrupt its program and service one or more peripheral devices requesting access to the m...

A hydraulic priority switch for preferential feeding of a low consumption primary loop in fluid communication with a hydraulic reservoir which is chargeable from a pressure medium source via a flow control means, against a non-preferential secondary loop which can be switched in with the aid of a priority value when said primary loop is sufficiently pressurized, said hydraulic priority switch having protecting means for protecting both loops from excess pressure comprising a pressure-limiting va...