Abstract: A computer system which includes a direct memory access (DMA) controller which can provide a 32 bit memory address and yet can also provide 24 bit memory address operation to remain compatible with previous systems. The DMA controller also monitors system operation and if only 24 bit address operations are occurring under the control of an external bus master or the DMA controller, the DMA controller drives the top memory address byte provided to a cache memory controller to help insure cache coherency. Additionally, the DMA controller can provide optimal time transfers for word width transfer between an odd starting memory address and an even starting input/output port.

Abstract: A rigid-flex printed circuit board having a rigid section and a flexible section extending from the rigid section is disclosed. The rigid-flex printed circuit board is capable of withstanding high temperatures experienced in high volume production environments utilizing infrared reflow ovens by providing spacers and covers for protecting the flexible section from high temperatures. A process for assembling components and devices on the rigid-flex printed circuit board in a high volume production environment utilizing infrared reflow ovens is also disclosed.

Abstract: An automatic line monitor for use in conjunction with a power supply for electronic components automatically accommodates either of two voltage ranges. Since the power supply may operate in domestic voltage ranges of about 100 volts or in international voltage ranges of about 120, the automatic line monitor senses and automatically switches to a voltage-doubling mode for the domestic range or a non-voltage-doubling mode for the higher international range. A latch may latch the line monitor in a non-voltage doubling mode once the higher voltage range is sensed. A monitor of a preferred embodiment eliminates almost all of the high-power-handling elements of the switch so that almost all of the operative elements of the switch may be incorporated on a single integrated circuit chip.