Browse Prior Art Database

ROS Checkout

IP.com Disclosure Number: IPCOM000067919D
Original Publication Date: 1979-Oct-01
Included in the Prior Art Database: 2005-Feb-20

Publishing Venue

IBM

Related People

Authors:
Abrahams, LC Swearingen, KW Woessner, RJ [+details]

Abstract

It is quite common in computer systems to use control storages and particularly read-only storages (ROS). It is desirable to have the ability to checkout the ROS unit at any time and particularly when a new ROS unit is field installed into the computer system. The checking arrangement should provide for detection of addressing failures and control word errors. Prior checking arrangements did not provide for checking the ROS address decode logic. The present checking arrangement provides for accumulating a count of the number of one bits as checking takes place and comparing the accumulated count with a count that resides in a ROS location in the unit under test. The count residing in ROS has bad parity for use as an indicator. This facilitates a check of the ROS address decode logic.