Browse Prior Art Database

DOS/AMAPs Use of Command Chaining

IP.com Disclosure Number: IPCOM000075225D
Original Publication Date: 1971-Aug-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Morse, HL: AUTHOR [+3]

Abstract

The Disk Operating System/Advanced Multiprogramming Analysis Procedure (DOS/AMAP) is a set of integrated programs and techniques for measuring thruput performance of a DOS environment. DOS/AMAP consists of a real-time trace, a set of data reduction programs and an event-driven model of the DOS Control Program.

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DOS/AMAPs Use of Command Chaining

The Disk Operating System/Advanced Multiprogramming Analysis Procedure (DOS/AMAP) is a set of integrated programs and techniques for measuring thruput performance of a DOS environment. DOS/AMAP consists of a real-time trace, a set of data reduction programs and an event-driven model of the DOS Control Program.

There are three specific areas of DOS/AMAP which are involved with command chaining. The DOS/AMAP Trace program captures the entire command chain for all programs that are running in the DOS environment while the tracing is active. The DOS/AMAP Edit 1 program manipulates the data for the command chains passed to it from the Trace and sets up the data in a format required by the DOS/AMAP Model. The DOS/AMAP Model simulates various environments using the command chaining data passed to it to simulate I/O operations accurately.

The use of the command chains by the DOS/AMAP Model permits more precise modeling of the following: 1) The rotational delay measured in half-revolutions for DASD operations. 2) Chained Write Check (Write Verify) operations. 3) The exact physical record length for each input-output operation rather than some statistical

average or maximum. 4) Multiple I/O operations contained within a chain which are executed by a single EXCP instruction. 5) Keeping a tape unit busy during a rewind operation for an unknown period of time. 6) Use of a page image for precise delay times for skipping, spacing and/or printin...