Browse Prior Art Database

Maintenance Scanner

IP.com Disclosure Number: IPCOM000097856D
Original Publication Date: 1961-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Wright, WV: AUTHOR [+2]

Abstract

A modern computer includes a memory, memory address register MAR., memory data register MDR, arithmetic units ADD, several registers J, K, L, M and data buses R and S. A program unit controls transfer of data between the registers, arithmetic units and memory locations specified by MAR. Memory addresses are developed from a stored program through manipulation of instruction addresses and by a special address generator which produces fixed addresses upon demand. Input-output units I/O connect via a buffer to MDR.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 62% of the total text.

Page 1 of 2

Maintenance Scanner

A modern computer includes a memory, memory address register MAR., memory data register MDR, arithmetic units ADD, several registers J, K, L, M and data buses R and S. A program unit controls transfer of data between the registers, arithmetic units and memory locations specified by MAR. Memory addresses are developed from a stored program through manipulation of instruction addresses and by a special address generator which produces fixed addresses upon demand. Input-output units I/O connect via a buffer to MDR.

Fault location and initial program loading are facilitated by a maintenance scanner in the program unit. All principal registers and control triggers of the computer are reflected in a scan area of memory.

The maintenance scanner controls the execution of the following operations:
1. Load. Data is transferred from a selected I/O unit to the

scan area.
2. Unload. Data is transferred from the scan area to a

selected I/O unit.
3. Scan-in. Data is transferred from the scan area to the

computer register and control triggers.
4. Scan-out. Data is transferred from the computer register

and control triggers to the scan area.
5. Cycle. The computer is allowed to operate in the normal

manner for the specified number of clock cycles.
6. Compare. Data is read from a selected I/O unit and compared

with the contents of the scan area.

A variety of maintenance functions is accomplished by execution of specific sequences of the above operations. Initia...