IBM C20-1649-3 DASD studentText free download

File name C20-1649-3_DASD_studentText.pdf

Student Text Introduction to IBM System/360 Direct Access Storage Devices and Organization Methods Preface This text discusses the physical characteristics and capacities of the following Direct Access Storage De- " vices available for System/360 Models 25, 30, 44, 50, 65, 67, 75, and 85: 2301 Drum Storage 2302 Disk Storage 2303 Drum Storage 2311 Disk Storage Drive 2314 Direct Access Storage Facility 2321 Data Cell Drive The file organization methods and access methods pro- vided for these devices by the IBM System/360 Op- erating System, the IBM System/360 Disk Operating System, and the IBM System/360 Basic Operating System are also discussed. The uses of direct access storage, basic terminology, and the establishment of controls for a direct access system are other topics addressed by this text. Most of the chapters end with student exercises, answers to which may be found at the end of the manual. No attempt at completeness is made. Refer to the publications listed in the Bibliography for additional details. MAJOR REVISION (April 1969) This edition, C20-1649-3, is a major revision of, and obsoletes, the previous edition, C20-1649-2. The significant changes in this edition are designated in three ways: 1. A vertical line appears at the left of affected text where only part of a page is changed. 2. A dot (.) appears at the left or right of the page number where a complete page should be reviewed. 3. A dot (.) appears at the left of the title of each figure that has been changed. Requests for copies of IBM publications should be made to your IBM representative or to the IBM branch office serving your locality. A form is provided at the back of this publication for readers' comments. If the .form has been removed, comments may be addressed to IBM, DP Education Development, Education Center, Endicott, New York 13760.