Browse Prior Art Database

SCSI Bus Routing for Internal and External Devices

IP.com Disclosure Number: IPCOM000108146D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 70K

Publishing Venue

IBM

Related People

Bistline, WR: AUTHOR [+2]

Abstract

Disclosed is a method of routing SCSI bus signals in a workstation to accommodate devices both internal and external to the computer. This method minimizes impedance mismatches, simplifies bus termination, and offers a convenient means of providing a secure SCSI option.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 98% of the total text.

SCSI Bus Routing for Internal and External Devices

      Disclosed is a method of routing SCSI bus signals in a
workstation to accommodate devices both internal and external to the
computer. This method minimizes impedance mismatches, simplifies bus
termination, and offers a convenient means of providing a secure SCSI
option.

      In the figure, the initiator represents a SCSI adapter on the
computer's motherboard.  A riser card plugged into a card edge
connector brings the SCSI data bus and control signals to the two
internal devices which are cabled to the riser card.  The SCSI
signals are then routed back down to the motherboard and over to the
external connector.  The external devices are cabled together in a
daisy-chain with a terminator at the last device on the SCSI bus.

      The riser card contains the termination network for the
initiator end of the SCSI bus; the initiator's transceivers are in
close proximity to the riser card connector.  Also, a set of jumpers
is housed on the riser card to support a secure SCSI configuration.
When the jumpers are removed, the SCSI bus connection to the external
connector is broken and only the internal devices are connected to
the SCSI bus.

      By routing the SCSI bus in a daisy-chain manner to the internal
and then the external devices via the riser card, impedance
mismatches are reduced, signal quality is maintained, bus termination
is simplified, and a secure SCSI configuration is supported.

    ...