Browse Prior Art Database

Verifying Peripheral Device Addresses

IP.com Disclosure Number: IPCOM000048254D
Original Publication Date: 1982-Jan-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Robinson, FL: AUTHOR [+2]

Abstract

In low-end data processing systems it is common practice for a user to install the system. When a plurality of peripheral devices are attached to such a small data processing system, the addressing of the peripheral devices has to be verified. A control unit interposed between the data processing system and the peripheral devices in a plural control unit setup causes a first control unit to test and assign addresses to the peripheral devices. The other control unit then writes the address to all of the devices. Then the first control unit reads the addresses from the devices from both control units and does a compare. If both control units have sent the appropriate address to the devices, then setup can continue by interaction between the user and the data processing system and the storage systems.

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Verifying Peripheral Device Addresses

In low-end data processing systems it is common practice for a user to install the system. When a plurality of peripheral devices are attached to such a small data processing system, the addressing of the peripheral devices has to be verified. A control unit interposed between the data processing system and the peripheral devices in a plural control unit setup causes a first control unit to test and assign addresses to the peripheral devices. The other control unit then writes the address to all of the devices. Then the first control unit reads the addresses from the devices from both control units and does a compare. If both control units have sent the appropriate address to the devices, then setup can continue by interaction between the user and the data processing system and the storage systems.

In the automatic portion of the setup procedure, the control units are identified by numbers beginning with zero. For a two-control unit setup, control unit zero and one operate the system and can access all of the peripheral devices whether magnetic tape units, disk apparatus, and the like. By arbitrary selection, control unit zero will be the master control unit. Control unit zero (CU0) waits until control unit one (CU1) which is connected to it, indicates over a control unit to control unit data path that it is ready to do a setup procedure. At that point, control unit zero sends out test signals to all of the attached periphera...