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
Scoring records for sorting by user-specific weights based on relative importance
Analysis, secure access to, and transmission of array images
Method and apparatus for band switching in wireless local access network
Resin composition and display device using the same
PC secure video path
White polyester film and surface light source therewith
Avalanche photo diode and method of manufacturing the same
  Randomly Featured Patents
Method of searching similar document, system for performing the same and program for processing the same
Hydraulically efficient ribbed pipe
System and method for flicker DC offset detection and correction
Semiconductor laser devices
Method and apparatus for limiting power amplifier voltage excursions
Solid electrolytic capacitor
Optical system for endoscope
Copying apparatus with front loading paper supply cassette
Comminuting machine
Multi-speed transmission