Secondary storage facility employing serial communications between drive and controller
US4825406A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1987 |
| Grant date | Apr 25, 1989 |
| Priority date | — |
| Expiry date | Mar 20, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0673
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a system including a plurality of mass storage devices at least one of which includes first and second ports, a plurality of controllers and cables coupling the ports to various ones of the controllers and in which each device can only be on-line through one port at a time, state information is sent from the on-line port of each device to a first controller to which it is coupled until a predetermined command from the controller to the on-line port is sent by the first controller. The device responds to the predetermined command by discontinuing the sending of state information from the on-line port to the first controller, and sending a state available signal from the other port to the second controller while maintaining the actual state of said device unchanged, permitting the other controller to interrogate the device as an aid in determining system topology.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.