Abstract: A system for charging compressed air cylinders with air for breathing incorporates a fragmentation containment chamber having walls of 1/4" minimum thickness steel plate and a carousel mounted in the front panel for transferring the cylinders into and out of the chamber. Specially configured locking plates are moved in and out of locking position for the carousel in accordance with the pressurizing operation. A rotary valve serves to insure that compressed air can only be transferred to the cylinders within the cylinder when they are in position for charging and not to the cylinders outside the chamber. A grating at the bottom of the chamber permits high pressure air to exit the chamber safely in case of any malfunction. Safety interlocks and automatic controls operate in accordance with rotation of the cylinders on the carousel results in the easy, rapid and safe charging of the breathing air cylinders.

Abstract: An in-circuit test system having means to stimulate the device-under-test at any desired electrical node of the device, means to record the device's response waveform at any node, means to edit the response waveform, and means to use the edited waveform to restimulate the same device in a subsequent in-circuit test.

Abstract: A circuit for use in an in-circuit digital tester for generating data bus and control line test signals to test the electrical performance properties of components in a circuit under test is disclosed. Certain components in a circuit under test, such as microprocessors, are bus oriented devices which perform their functions in predetermined cycles. These cycles have been divided up into control sequences of control signals. Sequences of data signals are also generated. Each test pin in the bed of nails test fixture has a digital test signal generator associated therewith. The present invention operates to program each test signal generator with digital test signal generating data to produce the control and data sequences required to test a device under test during a test cycle. These predetermined sequences in control and data sequences are specified by a sequence in starting addresses of the programmable memory locations containing the selected control and data sequences to be generated.

Abstract: A circuit for use in an in-circuit digital tester for generating data bus and control line test signals to test the electrical performance properties of components in a circuit under test is disclosed. Certain components in a circuit under test, such as microprocessors, are bus oriented devices which perform their functions in predetermined cycles. These cycles have been divided up into control signals and data bus signals. Each sequence of control signals are referred to as a protocol sequence. Each test pin in the bed of nails test fixture has a digital test signal generator associated therewith. The present invention operates to program each test signal generator with digital test signal generating data to produce each protocol sequence of the device under test. Test cycles are then run in which a predetermined sequence of protocol sequences are generated to test the device.