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
Inhibitors of bacterial nitric oxide synthase, and related screening methods
Chip on chip semiconductor device including an underfill layer having a resin containing an amine-based curing agent
Semiconductor devices having through electrodes and methods of fabricating the same
Human and mouse targeting peptides identified by phage display
Pyroelectric detector, pyroelectric detection device, and electronic instrument
Reserving a time block in a calendar application to account for a travel time between geographic locations of appointments
Reducing voltage stress in a flyback converter design
  Randomly Featured Patents
Nickel/indium alloy for use in the manufacture of electrical contact areas electrical devices
Cell culture method and apparatus for mechanically stimulating cells
Omnitable ride system
Cell permeable nanoconjugates of shell-crosslinked knedel (SCK) and peptide nucleic acids ("PNAs") with uniquely expressed or over-expressed mRNA targeting sequences for early diagnosis and th
Reverse pin for sucker rod tongs
Light-emitting device having a roughened surface with different topographies
Apparatus for removing oil from a compressed gas flow
Amperometric halogen control system
Apparatus and method for digitally obtaining signals having specified statistical distributions
System and method for MRI using MR signals from different resonant species in different regions of k-space