DSCB

Data Set Control Block

DSECT

Dummy Control SECTion

DSN

Data Set Name

DSNAME

Data Set NAME

DSNX

Distributed Systems Node

 

eXecutive

DSS

Data Set Services

DTF

Define The File

DTL

Define The Lock

EBCDIC

Extended Binary Coded

 

Decimal Interchange Code

ECB

Event Control Block

ECSA

Extended Common Service

 

Area

EMIF

ESCON Multiple Image

 

Facility

ENDREQ

END REQuest

ENQ

ENQueue

EOD

End Of Data

EOF

End Of File

EOJ

End Of Job

EOP

End Of Page

EP

Emulation Program

EQU

EQUate

EREP

Environmental error Record

 

Editing and Printing program

ERP

Enterprise Resource Planning

ESA

Enterprise Systems

 

Architecture

ESCON

Enterprise Systems

 

CONnection

ESD

External Symbol Dictionary

ESDS

Entry Sequenced Data Set

ESTAE

Extended Specify Task

 

Abnormal Exit

ETXR

End-of-Task eXit Routine

EXCP

EXecute Channel Program

EXLST

EXit LiST

FB

Fixed Block

FBA

Fixed Block Architecture

FCB

Forms Control Buffer

FCT

File Control Table

FD

File Definition

FDDI

Fiber Distributed Data

 

Interface

FEOV

Force End of Volume

FILESEC

FILE SECurity

FIPS

Federal Information

 

Processing Standard

FIT

Fast Implementation

 

Techniques

FM

File Mode

FORMDEF

FORMat DEFinition

FORTRAN

FORmula TRANslation

FSA

Functional Subsystem

 

Application

FSF

Forward Space File

FSI

Full Screen Interface

FSR

Forward Space Record

FSS

Functional SubSystem

FTP

File Transfer Program

GB

GigaByte

GCS

Group Control System

GDDM

Graphical Data Display

 

Manager

GDG

Generation Data Group

GFS

Get File Storage

GHN

Get Hold Next

GHU

Get Hold Unique

GML

Generalized Markup

 

Language

GN

Get Next

GRS

Global Resource Serialization

GSAM

Global Shared Access Method

GSR

Global Shared Resources

GTF

Generalized Trace Facility

GU

Get Unique

GUI

Graphical User Interface

HCD

Hardware Configuration

 

Definition

HD

Hierarchic Direct

HDAM

Hierarchic Direct Access

 

Method

HEX

HEXadecimal

HFS

Hierarchical File System

HIDAM

Hierarchic Indexed Direct

 

Access Method

HISAM

Hierarchic Indexed Sequential

 

Access Method

HLL

High Level Language

HMC

Hardware Management

 

Console

List of Abbreviations 585

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IBM OS/390 Data Set Control Block, Dummy Control SECTion, Data Set Name, Distributed Systems Node, Data Set Services, Area

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.