JES2/POWER functional comparison (continued) output service (continued)

printers supported 216 separator page differences 217 tape spooling 216

UCS naming conventions 218 RAS characteristics

remote job entry

functional RJE differences 219 remote workstation definitions 219 RJE exits 220

RJE operations 220 JES3 21, 151

job 70 accounting 223

execution serialization 214 information services 222 input 73

layout 72 log JES2 395 name 275, 549

roles & normal activities 26 schedulers 50 scheduling 213

scheduling functions with MVS/JES2 214 simulation 515

step 70

step definition 72 stream 70

stream disposition 213 submission 439

time event scheduling 208 tracking 441

Job Control Language 15 See also JCL

batch job control 451 MVS JC statements 84 philosophy of OS/390 job control 70 VSE JC statements 82

Job Entry Control Language 89

JOB statement 82

JOB statement starts a job 72 JOBCAT statement 117 journaling to tape 137 Julian date definition 574

K

KEEP disposition for pre-execution jobs 207 kernel/progressive approach 27

L

label processing bypass 106 labels 103, 105, 106

language differences DOS/VS COBOL and COBOL for OS/390 and VM 253

Language Environment (LE) 351

abnormal termination exits 365

Language Environment (LE) (continued)

conceptual differences between LE/VSE and OS/390

Language Environment

 

352

 

 

 

differences between LE/VSE & OS/390 Language

Environment

 

352

 

 

 

 

 

general comments on Language Environment

about COBOL and PL/I

351

 

 

 

introduction

 

351

 

 

 

 

 

 

LE/VSE-conforming languages

353

 

locales

366

 

 

 

 

 

 

 

 

migrating from LE/VSE

359

 

 

 

migrating from LE/VSE-conforming languages 353

migrating from non-LE/VSE run-time

 

environments

354

 

 

 

 

 

migration

359

 

 

 

 

 

 

 

migration considerations VSE to OS/390

352

publications

 

353

 

 

 

 

 

 

using C socket API for TCP/IP

196

 

LE/VSE

 

 

 

 

 

 

 

 

 

 

 

1.4 locales

366

 

 

 

 

 

 

 

conforming languages

352, 353

 

 

migration

359

 

 

 

 

 

 

 

user exits

364

 

 

 

 

 

 

 

leap year definition

574

 

 

 

 

 

Librarian

43, 98, 389

 

 

 

 

 

 

library

 

 

 

 

 

 

 

 

 

 

 

command language

389

 

 

 

 

data format

 

389

 

 

 

 

 

 

interactive usage

390

 

 

 

 

 

logical structure

389

 

 

 

 

 

management

391

 

 

 

 

 

 

OS/390 ISPF overview

390

 

 

 

sharing

432

 

 

 

 

 

 

 

 

support

389

 

 

 

 

 

 

 

 

Lilian date definition

574

 

 

 

 

 

LIMSCONV

336

 

 

 

 

 

 

 

 

LINK

336

 

 

 

 

 

 

 

 

 

 

linkage macros

271

 

 

 

 

 

 

linkages between languages

338

 

 

 

linkages not supported

338

 

 

 

linkages supported

338

 

 

 

 

LIOCS

 

 

 

 

 

 

 

 

 

 

 

card file definition

294

 

 

 

 

 

Console File Definition

304

 

 

 

Device-independent File Definition

303

 

direct access file definition

311

 

 

indexed sequential file definition

326

 

printer file definition 296

 

 

 

 

sequential file definition on Direct Access

304

tape file definition

297

 

 

 

 

 

List & Execute macro forms

293

 

 

 

LIST card - * $$ LST

89

 

 

 

 

 

LISTLOG utility

393

 

 

 

 

 

 

LMESSAGE

337

 

 

 

 

 

 

 

LOAD macro

277

 

 

 

 

 

 

 

loading a DAM File (fixed-length records with

keys)

319

 

 

 

 

 

 

 

 

 

Index 605

Page 629
Image 629
IBM OS/390 manual Le/Vse, Limsconv, Link, Liocs, Lmessage

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.