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
Titanium compounds and complexes as additives in lubricants
Curable sublimation marking material and sublimation transfer process using same
Magnesium metal-air battery
Vacuum cleaner
SONOS stack with split nitride memory layer
Binary-to-gray converting circuits and gray code counter including the same
Processor and data transfer method
  Randomly Featured Patents
Peripheral device, search result storage method and computer program product
Laser atherectomy catheter
Bottle security device
Electronic control apparatus with defined reset function
Firework launching platform apparatus
Telephone user interface programmable shortcut
Self-bonding room temperature vulcanizable silicone rubber compositions
Front air knife top vacuum corrugation feeder
One-way valve on diving mask
Method of processing a color image to obtain color and black reproduction signals