Abstract: A barbell collar includes a collar and sleeve arrangement that are telescopingly displaceable relative to one another to permit adjustment along a barbell support rod. Retractable detent spheres are mounted within the sleeve for engagement with annular grooves of the barbell to effect selective securement and positioning of the sleeve structure relative to the barbell rod.

Abstract: Portable test apparatus for tracing faults in electronic equipment including or associated with a microprocessor comprises a control module connectible to a test configuring module. The control module comprises a microprocessor, a data storage memory programmed to contain operating software associated with the microprocessor, a keyboard and visual display screen for enabling intercommunication between a user of the apparatus and the microprocessor, and a data bus for data transfer between the control module and the test configuring module. The test configuring module comprises a data storage memory programmed to contain a range of diagnostic tests specific to a particular type of electronic equipment to be tested and accessible by the microprocessor, and a latched data bus for data transfer between the test configuring module and the unit to be tested. Faults can be traced to a general area (RAM, ROM, I/O, etc.