Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
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
Three-dimensional filter
Oxidative coupling of hydrocarbons as heat source
(4938
Lubricant composition
Method and system for advertisement using internet browser to insert advertisements
Optical fixing device and image forming apparatus
Squib control circuit
  Randomly Featured Patents
Gravel pack completion with fiber optic monitoring
Time reservation using adaptive control for energy efficiency
Interspinous process implants and methods of use
Treatment and prevention of immunodeficiency virus infection by administration of non-pyrogenic derivatives of lipid A
Method and apparatus for breaking concrete or the like
Methods and systems for producing off-shore deep-water wells
Device for preventing plating of material in surface openings of turbine airfoils
Carbon electrode cleaning system
Electronic musical instrument with improved generation of wind instruments
Abrasive machine for machining a flange on a work piece