Resources Contact Us Home
Computer system having a bridge between two buses with a direct memory access controller and an alternative memory access controller

Image Number 3 for United States Patent #5621902.

A computer system having a peripheral controller interconnect (PCI) bus and an industry standard architecture (ISA), with ISA compatible devices coupled to the ISA bus, is provided with a first bridge coupled between the PCI and ISA buses. The first bridge has a first direct memory access (DMA) control circuit for controlling DMA transfers with the ISA devices. In order to achieve expanded compatibility with other types of devices, the system is also provided with an expansion bus, such as a Microchannel bus, with Microchannel compatible devices coupled to the Microchannel bus. A second bridge is coupled between the PCI and the Microchannel buses. This second bridge has a second DMA control circuit that controls DMA transfers with the ISA devices and with the Microchannel devices. Software disables the first DMA control circuit such that only the second DMA control circuit controls DMA transfers within the computer system.

  Recently Added Patents
Profile and template based dynamic portable user workflow
Cosmetic composition based on a supramolecular polymer and a hyperbranched functional polymer
Base station apparatus and communication control method
Human renal disease marker substance
Memory cell and memory cell array using the same
Ice tray for refrigerator
Upper surface of a skateboard deck
  Randomly Featured Patents
Auxiliary translation lookaside buffer for assisting in accessing data in remote address spaces
Fan and vibration-absorbing boss thereof
Method for measuring neurotransmitters in vivo
Computer attachable to an undersurface of a desk
Ester compounds, polymers, resist composition and patterning process
Method of forming electrically conductive polymer interconnects on electrical substrates
Bandwidth reduction for stereoscopic imagery and video signals
Process for manufacturing fiber reinforced light metal castings
Dual guidewire exchange catheter system
Image forming apparatus including a stopping unit and method of forming image