Abstract: A personal computer system utilizes a simplified motherboard having connectors on the motherboard that are electrically connected to data, address, control, power and ground signals necessary for expansion and upgrade of the computer system and a riser card or cards having the desired interface connectors and logic circuits thereon. The present invention provides for operatively and removably coupling a plurality of I/O expansion cards, host local bus interfaces and future system upgrades for the computer system without burdening the base cost thereof. The computer system may be expanded or upgraded at any time during manufacture or in the field. A simple and low cost common motherboard is utilized in the manufacture of the computer systems, resulting in lower manufacturing costs. A base computer system may be easily upgraded when more features are desired.

Abstract: A leadless high density connector including a plurality of connector pins each having multiconductor pins electrically connected to solder balls on the back side of the connector for interconnection to a PWB. The solder balls form a ball grid array (BGA), which replaces thin gull wing leads used on connectors of prior art. The use of BGA technology as applied to high density connectors provides a plurality of benefits associated with BGA technology. The signal carrying capacity of the connector is increased since the bottom surface of the connector is available for interconnecting signal paths rather than being limited to the peripheral edges as common for leaded packages. The resulting profile of the connector is substantially reduced allowing increased component and wiring density. The resulting bond strength using BGA technology is greater than that with a leaded equivalent due to the increased bond surface area and resulting anchoring effect.

Abstract: An apparatus and method for a computer system that selectively disables expansion peripheral interface devices so that they do not interfere with diagnostic testing of related computer system peripheral interface devices. The present invention selectively disables the peripheral interface devices by control of the clock signals thereto. The clock signals may be selectively controlled by means of a software test program that may also be used to automate the diagnostic testing of the computer system. In addition, the computer system may be remotely tested and diagnosed because the present invention makes it unnecessary for the physical removal of devices that may cause false signal responses during the diagnostic tests.

Abstract: A personal computer system utilizes a simplified motherboard having connectors on the motherboard that are electrically connected to data, address, control, power and ground signals necessary for expansion and upgrade of the computer system and a riser card or cards having the desired interface connectors and logic circuits thereon. The present invention provides for operatively and removably coupling a plurality of I/O expansion cards, host local bus interfaces and future system upgrades for the computer system without burdening the base cost thereof. The computer system may be expanded or upgraded at any time during manufacture or in the field. A simple and low cost common motherboard is utilized in the manufacture of the computer systems, resulting in lower manufacturing costs. A base computer system may be easily upgraded when more features are desired.