Abstract: An apparatus is described for burn-in and/or functional testing of microelectronic circuits of unsingulated wafers. A large number of power, ground, and signal connections can be made to a large number of contacts on a wafer. The apparatus has a cartridge that allows for fanning-in of electric paths. A distribution board has a plurality of interfaces that are strategically positioned to provide a dense configuration. The interfaces are connected through flexible attachments to an array of first connector modules. Each one of the first connector modules can be independently connected to a respective one of a plurality of second connector modules, thereby reducing stresses on a frame of the apparatus. Further features include for example a piston that allows for tight control of forces exerted by terminals onto contacts of a wafer.

Abstract: A clock generation circuit includes a reference clock for putting out a stable reference clocking signal. A digital ring oscillator includes a series circuit loop having at least one inverting gate and a programmable delay line of plural delays formed a series of tapped digital transmission gates connected between an output and an input of the inverting gate. A multiplexer selects among the series of taps in accordance with a tap selection signal. A clock monitoring circuit is connected to compare the clock output with a stable reference clocking signal to produce a digital clock cycle count. A programmed microcontroller generates the tap selection value as a function of the digital clock cycle count and a desired clock output frequency set point.

Abstract: A removable and transportable hard disk subsystem is provided for use with at least one computer and includes at least one hard disk module. The module contains a shock mounted, thin and compact micro-Winchester head and disk assembly which plugs into a base housing which is installable entirely within a well of the computer nominally allotted to receive a 51/4 inch half height disk drive. The base housing includes a head positioning and data module loading/unloading portion of the subsystem control electronics and an electromechanical mechanism for automatically loading and unloading the hard disk module. The base housing provides electrical connections for operating the head and disk assembly when loaded therein.

Abstract: A solid state memory array includes an address bus and a bidirectional data bus and a plurality of partly defective VLSI memory array chips each containing at least one megabit of data storage capacity, having defective memory cell locations, being connected to the address bus, and providing plural data storage bit positions. Each memory array chip has a bidirectional tri-state driver connected between the bit lines thereof and corresponding ones of the data bus. At least one VLSI substitution memory chip contains at least one megabyte of data storage capacity, is connected to the address bus and provides plural data storage bit positions. A substitution chip tri-state driver is connected between the bit lines of the substitution memory chip and all of the parallel data bit lines of the data bus.

Abstract: A removable and transportable hard disk subsystem is provided for use with at least one computer and includes at least one hard disk module. The module contains a shock mounted, thin and compact micro-Winchester head and disk assembly which plugs into a base housing which is installable entirely within a well of the computer nominally allotted to receive a 51/4 inch half height disk drive. The base housing includes a head positioning and data module loading/unloading portion of the subsystem control electronics and an electromechanical mechanism for automatically loading and unloading the hard disk module. The base housing provides electrical connections for operating the head and disk assembly when loaded therein.

Abstract: A removable and transportable hard disk subsystem is provided for use with at least one computer and includes at least one hard disk module. The module contains a shock mounted, thin and compact micro-Winchester head and disk assembly which plugs into a base housing which is installable entirely within a well of the computer nominally allotted to receive a 51/4 inch half height disk drive. The base housing includes a head positioning and data module loading/unloading portion of the subsystem control electronics and an electromechanical mechanism for automatically loading and unloading the hard disk module. The base housing provides electrical connections for operating the head and disk assembly when loaded therein.