l1 Mfcics Mvs Student Guide

8/13/2019 l1 Mfcics Mvs Student Guide

1/97

Patni Computer Systems Ltd

MVS

Student Guide

Copyright 2008 Patni Computer Systems Ltd., Akruti, MIDC Cross Road No. 21, Andheri (E), Mumbai

400 093. All rights reserved. No part of this publication can be reproduced in any way, including but not

limited to photocopy, photographic, magnetic, or other record, without the prior agreement and written

permission of Patni Computer Systems.

Patni Computer Systems considers information included in this document to be Confidential and

Proprietary


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Copyright 2008 by Patni

Table of Contents

1 INTRODUCTION................................................................................................................................1

2 OPERATING SYSTEM CONCEPTS..................................................................................................2

2.1 OPERATING SYSTEM IMPORTANCE AND NEED ...............................................................................2

2.2 POSITION OF OS IN A SYSTEM ........................................................................................................2

3 COMPUTING ENVIRONMENT..........................................................................................................4

3.1 KEY CONCEPTS AND TERMINOLOGY................................................................................................4

3.2 DATA PROCESSING .......................................................................................................................4

3.3 MULTI-PROGRAMMING ...................................................................................................................5

3.4 MULTI-PROGRAMMING OVERHEADS................................................................................................6

3.5 RELEVANCE OF MULTI-PROGRAMMING ............................................................................................6

3.6 MULTI-PROCESSING ......................................................................................................................6

3.7 SPOOLING ....................................................................................................................................7

3.8 VIRTUAL STORAGE ........................................................................................................................7

3.9 MEMORY MANAGEMENT.................................................................................................................8

4 CHARACTERISTICS FEATURES OF MVS ....................................................................................10

5 IBM OPERATING SYSTEMS ..........................................................................................................11

5.1 IBM FAMILIES OF OPERATING SYSTEMS........................................................................................11

5.2 MVS EVOLUTION ........................................................................................................................12

5.3 MULTIPROGRAMMING W ITH FIXED TASK (MFT)..............................................................................14

5.4 MULTIPROGRAMMING W ITH VARIABLE TASKS (MVT) ......................................................................15

5.5 SYSTEM 370 I/O ARCHITECTURE ..................................................................................................19

6 KEY TERMINOLOGY ......................................................................................................................21

6.1 CACHE MEMORY .........................................................................................................................21

6.2 CHANNELS ..................................................................................................................................21

6.3 CHANNEL - I /ODEVICE CONNECTIVITY ..........................................................................................21

6.4 I/O DEVICES ...............................................................................................................................21

6.5 DATA COMMUNICATION NETWORK ................................................................................................22

6.6 DATA COMMUNICATION EQUIPMENT ..............................................................................................23

7 TYPICAL MAINFRAME CONFIGURATION ....................................................................................26

7.1 A SMALL MAINFRAME CONFIGURATION .........................................................................................26

7.2 MVS CONCEPTS AND TERMINOLOGY ............................................................................................27

7.3 RSM (REAL STORAGE MANAGER)................................................................................................307.4 ASM (AUXILIARY STORAGE MANAGER).........................................................................................30

7.5 VSM (VIRTUAL STORAGE MANAGER)............................................................................................30

7.6 VIRTUAL STORAGE LAYOUT..........................................................................................................31

8 MVS FUNCTIONS ...........................................................................................................................33

8.1 DATA MANAGEMENT OVERVIEW ...................................................................................................33

8.2 TYPES OF DATA ..........................................................................................................................33

8.3 DATASET ORGANIZATION .............................................................................................................33


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8.4 NON-VSAM DATASETS ORGANIZATION..........................................................................................34

8.5 DATASET ORGANIZATION .............................................................................................................34

8.6 VSAM DATASETS ORGANIZATION..................................................................................................36

8.7 DATA ORGANIZATION - SALIENT POINTS........................................................................................36

8.8 DATA SET NAMING RULES ...........................................................................................................36

8.9 MVS DATASETS ..........................................................................................................................378.10 DATA MANAGEMENT ....................................................................................................................39

8.11 HOW DATASETS ARE ACCESSED? .................................................................................................40

9 JOB MANAGEMENT OVERVIEW...................................................................................................41

9.1 WHAT IS A JOB?..........................................................................................................................41

9.2 JOB MANAGEMENT FUNCTIONS ....................................................................................................41

9.3 STAGES OF JOB ..........................................................................................................................41

9.4 JOB MANAGEMENT ......................................................................................................................42

9.5 JOB SCHEDULING ........................................................................................................................43

10 DATASET ALLOCATION AND JOB STEP EXECUTION ...............................................................46

11 MVS TOOLS OVERVIEW................................................................................................................48

11.1 JOB MANAGEMENT TOOLS ...........................................................................................................48

11.2 WHY AND WHAT OF JCL? ............................................................................................................49

11.3 JES - JOB ENTRY SYSTEM...........................................................................................................49

11.4 MVS TOOLS OVERVIEW ...............................................................................................................50

11.5 COMPONENTS OF JOB OUTPUT.....................................................................................................53

11.6 VTAM VIRTUAL TELECOMMUNICATIONSACCESS METHOD...........................................................54

11.7 CICS CUSTOMER INFORMATION CONTROL PROGRAM (OPTIONAL COMPONENT) ............................55

11.8 DB2 - DATABASE 2 (OPTIONAL COMPONENT).................................................................................55

11.9 RACF - RESOURCEACCESS CONTROL FACILITY ...........................................................................55

11.10 SMF - SYSTEM MANAGEMENT FACILITY.....................................................................................55

11.11 LANGUAGE TRANSLATORS / LINKAGE EDITOR / LOADER ..............................................................5611.12 UTILITIES ................................................................................................................................56

11.13 AN INTRODUCTION TO TSO ......................................................................................................56

12 INTERACTIVE SYSTEM PRODUCTIVITY FACILITY (ISPF) ..........................................................58

12.1 PRIMARY OPTIONS MENU ............................................................................................................58

12.2 TERMINATION PANEL ...................................................................................................................60

12.3 KEY MAPPING .............................................................................................................................60

12.4 BROWSING DATASETS (OPTION 1)................................................................................................61

12.5 BROWSE COMMANDS...................................................................................................................62

12.6 EDITING DATASETS (OPTION 2) ....................................................................................................62

12.7 STANDARD EDITING COMMANDS ....................................................................................................62

12.8 EDIT PROFILES ...........................................................................................................................6312.9 PROFILE SETTINGS......................................................................................................................64

12.10 EDIT MODES............................................................................................................................64

12.11 ADVANCED EDIT OPTIONS ........................................................................................................65

12.12 SHIFTING TEXT SOURCE............................................................................................................65

12.13 UTILITIES MENU .......................................................................................................................66

12.14 LIBRARY UTILITY......................................................................................................................67

12.15 DATASET UTILITY .....................................................................................................................68

12.16 NEW DATASET ALLOCATION.......................................................................................................68


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12.17 RENAMING DATASET ................................................................................................................69

12.18 DATASET INFORMATION ............................................................................................................69

12.19 ALLOCATING DATASETS............................................................................................................70

12.20 MOVE / COPY ..........................................................................................................................71

12.21 MOVE / COPY- 2 ......................................................................................................................72

12.22 DSLIST UTILITY ......................................................................................................................7312.23 DSLIST DATASET SELECTION ..................................................................................................73

12.24 DSLIST COMMANDS................................................................................................................74

12.25 PRIMARY COMMANDS...............................................................................................................74

12.26 RESET ....................................................................................................................................75

13 DIFFERENCES BETWEEN TEST AND PRODUCTION ENVIRONMENTS .................................76

14 INTRODUCTION TO FILE-AID........................................................................................................77

14.1 F.1 BROWSE...............................................................................................................................77

14.2 F.1 BROWSE SCREEN ..................................................................................................................79

14.3 F.2 EDIT .....................................................................................................................................82

14.4 F.3 UTILITIES...........................................................................................................................83

15 APPENDIX A (BIBLIOGRAPHY/REFERENCES).........................................................................92


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Day-Wise Schedule

Day 1

Computing Environment -Key Concepts & terminology, Typical IBM MF site.

IBM Operating Systems -

IBM families of OS

IBM Hardware

MVS Implementation

MVS Functions

Data Management Overview

Job Management Overview

MVS Tools Overview

Lab session

Demo on ISPF

Familiarizing with various options of ISPF editor on PCCICS

Assignments ISPF editor

Differences between Test and Production Environment

Introduction to File-Aid (This just gives an introduction to File-Aid and refer to IBM

Manual for further details)


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Copyright 2008 by Patni Page 1 of 97

1 INTRODUCTION

Before you begin to work on the Mainframe environment, which by default means IBM Mainframe,

you need to have a basic idea of the IBM mainframe operating system. Today, it is know as MVS, which

expands to Multiple Virtual Storage.

The MVS operating system has evolved over many years and has adapted to the changing technology

and modern day requirements. Since the user base of MVS is very large, a change is not easy to

Implement. The costs of the Mainframes are very high and the customer base is mostly made up of

long-term customers with huge application and large databases to support. Most of these applications

are also Mission Critical applications. It is therefore imperative that any change to MVS also be

backward compatible.

MVS is designed to work with many hundreds of users working together, located in the same locality or

across continents. The MVS operating System was created by IBM and is said to propriety OS. It has

the capacity to supports a large number of peripherals like disks, tapes, printers, Network devices etc.The applications on these Legacy systems are typically where there is a huge amount of data and a

large user base. Examples are banking sector, Insurance Sector, Newspapers, Material and Inventory,

Airlines, Credit Card System, Billing, Accounting, Shipping and others. Companys that own these

mainframes are typically those that are very big inherently or have to deal with vast amounts of data,

which has to be processed fast.


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2 OPERATING SYSTEM CONCEPTS

2.1 OPERATING SYSTEM IMPORTANCE AND NEED

An OS controls the computer and acts as an intermediary between the user of a computer and

the computer hardware. The OS basically programs the task of scheduling the use of the

computer. Sophisticated OSs increase the efficiency of use of the computer and hence reduce

the cost of using the computer.

2.2 POSITION OF OS IN A SYSTEM

Users

Users

Application Programs

Utilities

Loaders

Linkers Compilers

OS manages

Memory Device

Information Processor

Hardware


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The main functions of the Operating System are:

Keeping track of the resources namely memory, I/O devices, processor and information.

Decides who gets what resource, and how much?

Allocate the resources when needed.

Reclaim the resources back after it has been used, so that they may be allocated subsequently.


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3 COMPUTING ENVIRONMENT

3.1 KEY CONCEPTS AND TERMINOLOGY

Command Processing

Command Issue Mode

This how a user (programmer / end-user) interacts with the computer E.g. To edit a program, toexecute a program

On-line Mode - Using TerminalBatch Mode - Using Punched Cards or JCLs

Command Execution Mode

All computer commands can be executed in two modes

Foreground - Terminal is locked while the command is being executedBackground - Terminal is free while the command is being executed

3.2 DATA PROCESSING

How Business applications are executed

On-line

End User performs business functions

Application programs work interactively with End User

Execution is in foreground mode

Database is immediately updated to reflect the changes

Typically used for transaction processing, queries, master updates functions

Batch

Application programs are executed in background mode

Periodic business functions are executed automatically

As and when business functions are triggered by End User

Operations department is responsible for monitoring the execution

A command file is created to execute these functions


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One command file may consist of multiple programs / system utilities

Typically used for bulk transaction processing, report printing, periodic processing (e.g. invoice generation,payroll calculation)

Time Sharing

1. Resource Sharing

2. Multiple Users compete for computer resources at the same time

3. At any given point in time only one user can have control of the resources

4. What should be the basis of sharing?

First come first served?

Priority based?

Who so ever can grab it - Law of Jungle?

Equal - Democratically?

Need based?

Usually combination of 2 and 4 is used i.e. all are equal but some are more equal!!!

Time Slice

Each user is given control of resources for a pre-defined period - time slice

The control is passed on to next in queue user at the end of time slice (even if first users

work is incomplete)

If the user requires I/O before the time slice is over, the control is handed over to the next

user (since CPU cannot do anything until I/O is complete)

Priority

Each user / function is assigned a priority level

The higher priority users are serviced first in a round robin fashion

Only if the higher priority users are in wait state for I/O completion the users in the lower

priority are serviced

Time Sharing typically refers to sharing of resources in an interactive processing mode.

3.3 MULTI-PROGRAMMING

Why Multi-Programming?

The program has CPU based and Non-CPU based instructions

CPU is kept waiting during the non-CPU based instructions execution

E.g. I/O operations (Disk, Terminal, Printer)


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This results in wastage of CPU time - a precious resource

Multi-programming results in better CPU utilization

How does it Work?

Multiple programs are kept ready for execution

CPU can execute only one program at any given point in time

If the currently executing program requires I/O, it is put in a wait state

Another program is immediately taken for execution

On completion of I/O the program again becomes ready for execution

This results in an illusion that multiple programs are being executed simultaneously, hence

multiprogramming.

3.4 MULTI-PROGRAMMING OVERHEADS

Program Queue Management

Program Status Management

Context Switching during Changeover

Multiple programs must be in main memory

Management of Common Resource Sharing (e.g. Printer)

It is critical to determine optimum level of Multi-programming to maintain certain service level.

3.5 RELEVANCE OF MULTI-PROGRAMMING

Multi-programming is applicable even for single user system

Multi-programming is a must for multi-user system

3.6 MULTI-PROCESSING

There are multiple CPUs (processors) in one machine

These work together under single operating system

Each CPU executes a separate program

O/S assigns programs to each CPU

Essentially CPU is treated as an allocable device!!!!!


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3.7 SPOOLING

Why Spooling?

Multiple programs may need same printer at the same time

May result in intermixing of output Exclusive access to a program will hold other programs

Printer is much slower, results in longer wait state

How it is implemented?

Output to printer is intercepted and written to a disk i.e. spooled

On completion of program spooled output is queued for Printing

This queue is processed by O/S print routine

The O/S print routine is multi-programmed along with application programs

3.8 VIRTUAL STORAGE

Why Virtual Storage?

Required to enable execution of programs with are larger than the main memory size

What is Virtual Storage?

Technique to simulate large amount of main storage

Reality is main storage is much less

E.g. Real main storage is 16MB but virtual storage is 2GB

How Virtual Storage is implemented?

Program executable code is generated assuming virtual storage size

Only part of the program is loaded in main memory

Address translation mechanism is used to map virtual address to actual address

Feasible because only the instruction currently being executed and the corresponding data needto be in the main storage

Advantages of Virtual Storage

Main memory can be shared by multiple programs


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Enables effective use of the limited main storage

Overheads of Virtual Storage

Address mapping

Keeping track of what is in memory and what is not

Data/Instructions need to be brought in main memory as an when required

Remove from main memory what is not currently required (to make room for instructions of

other program)

Memory Management

3.9 MEMORY MANAGEMENT

Problem: - Any thing that is to be executed must be in memory. (Memory limitation)

Solution: - 1. Place task in real memory

2. Place task in virtual memory

1. Real Memory implementation:

Code and data are in real memory

Size of code and data limited by size of installed memory

Good performance, low overhead

Possible wastage of memory

2. Virtual memory implementation:

Based on assumption for a task, not all code & data is needed in real memory all the time

Implemented on a combination of real plus auxiliary storage

Operating system takes responsibility of bringing rest part of tasks in real memory when required


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4 CHARACTERISTICS FEATURES OF MVS

1) VIRTUAL STORAGE: The use of virtual storage increases the number of storage locations available

to hold programs and data.

2) MULTIPROGRAMMING: Multiprogramming simply reclaims the CPU during idle periods to let other

programs execute.

3) SPOOLING: To provide shared access to printer devices.

4) BATCH PROCESSING: When batch processing is used, work is processed in units called Jobs. A

job may cause one or more programs to be executed in sequence. The system collectively

processes batch jobs.

5) TIMESHARING: In this system, each user has access to the system through a terminal device.

Instead of submitting jobs that are scheduled for later execution, the user enters commands that are

processed immediately.

Time-sharing is also called Online Processing because it lets users interact directly with the computer.


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5 IBM OPERATING SYSTEMS

5.1 IBM FAMILIES OF OPERATING SYSTEMS

DOS - Disk Operating

System

For Small

System/360

DOS/VSE

(Virtual Storage

Extended)

VM/CMS - Virtual

MachineConversation Monitor

System

Simulates more than

one computer system

on single real machine

Supports both DOSand OS

OS - Operating System

For Full range

System/360

MVS

(Multiple Virtual

Storage)


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5.2 MVS EVOLUTION

1995 MVS/ESA 5.2.2

1993 MVS/OPEN EDITION (POSIX)

1990 SYSTEM 390

1988 MVS/ESA 16 B

1981 MVS/XA 2 GB (31-bit)

1974 OS/VS2R2 (MVS) 16 MB (24-bit)

1972 OS/VS1 OS/VS2R1 (SVS) 16 MB

1970 SYSTEM 370

1966 OS/MFT OS/MVT 3 MB

1966 PRIMARY CONTROL PROGRAM (PCP)


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PCP Primary Control Program

Basically a PrimerIntroduction of JCL-(JOB Control Language)(Became obsolete 1n1969

No MultiprogrammingNo PriorityNo SpoolingVery unreliable

1966 MFT Multi-programming with

Fixed number of Tasks

Limited multi-programmingSmall improvementover PCP

Storage allocated as perrequirement (region)No. of Jobs dependsupon storage req. andavailability

1967/68 MVTMulti-programming with

Variable number of Tasks

Reliable ComprehensivefeaturesPredecessor of MVS

Fixed Number of PartitionsOne Job per PartitionFixed Partition Size

Operating Systems for

System/360

1965


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Single Contiguous Allocation

In the earlier OSs like OS/360 PCP (Primary Control Program), which was a batch Operating System,

where there is no multiprogramming, memory is allocated to a job as follows.

Area of memory available for use by the

program

The OS occupies a portion of the memory and the remaining area of the memory is allocated to the user

program. If the program is smaller than the remaining memory, then there is some unused space in thememory, which goes waste. On the other hand the program that does not fit in memory cannot be

executed at all.

Disadvantages

The memory is not fully utilized

CPU has to wait on the job when an I/O is being performed

Some portions of the program in the memory may not be accessed at all

Hence there is a poor utilization of memory and the CPU and the job size is limited to maximum memory

available, after use by the OS.

5.3 MULTIPROGRAMMING WITH FIXED TASK (MFT)

This type of memory management is also called Static Partition Specification.

Here the size of each partition is decided at the time of installation of the OS, this remains fixed after the

OS is loaded and cannot be changed. To change the size of the partition the OS must be reinstalled,

during which the changes are incorporated.

A Partition Status Table, which is shown in the figure, is used to keep track of the use of partitions.

Operating System

Memory area used by

this program

Allocated but not used

(Wasted)


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Partition No Size Status

1 8K In use

2 32K In use

3 32K Not in use

4 120K Not in use

5 520K Not in use

When the user gives a job, he has to specify the maximum memory needed to run it. A partition of

sufficient size is then found and assigned.

This system is satisfactory when the size of the job is almost equal to the partition size. If the size of the

job is diverse then there might be considerable wastage of memory space.

For E.g.: When a job requires 33K, then partition 4 is used (see table) resulting in a colossal waste of

around 87K. At the time of execution of this 33K job, if another job of 80K is to be submitted, assumingpartition 5 (520K size) is already in use, the new job has to wait (as it can be accommodated only in

partition 4 or 5).

5.4 MULTIPROGRAMMING WITH VARIABLE TASKS (MVT)

Thus it becomes important that the appropriate partitions are to be allocated to the appropriate Jobs

depending upon the size, so that all partitions are effectively utilized with minimum space wastage.

This is called the Dynamic Specification. This implies that the partitions are created as and when job is

processed. Here again partition status tables are used.

When a job is to be processed, then a free contiguous area at least as large as the partition desired

must be found. Second, if the area found is large than required, it must be split into allocated and

unallocated portions of the system.

Migrating from Dos to OS was a major change

VM is not very popular

Today most of the sites use MVS

Major Handicaps

Limited and inefficient spooling

No Virtual Storage

Utilities to Overcome these Handicaps

HASP - Houston Automatic Spooling Priority

Developed unofficially (self initiative) by IBM employees

Distributed free to MVT/MFT users

Became very popular


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Eventually owned and supported by IBM

ASP - Attached Support Processor

Developed (officially) by IBM

Intended for MVT

Several mainframes can work together under single O/S (predecessor of multi-processing?)

Provided better spooling capability

Relatively less takers

System 370

Announced in early 70s

Supported Virtual Storage

New Operating Systems OS/VS were introduced

OS/VS1 (Virtual System 1) - adopted from MFT

OS/VS2 (Virtual System 2)

Version SVS - Single Virtual Storage

Adopted from MVT (1972)

Version MVS - Multiple Virtual Storage Completely Rewritten (1974)

HASP and ASP were migrated to OS/VS2 under the names JES2 and JES3

MVS and its derivatives are the mainstay of IBM O/S now


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1974 OS MVS/SP1 Multiple Virtual Storage

/VS2 System/37024 bit addressability

Greater reliability /

integrity / performance

Virtual storage limitationof 16MB - A serious

handicap for CICS

1983

Processors :

308x, 3090, 4381

1988

MVS MVS/SP3 Multiple Virtual Storage

/ESA Enterprise Systems ArchitectureESA/370

Processors :

ES/3090 E and S Models and later

4381 Models 90E, 92E, 93E and later

1990MVS MVS/SP4 Multiple Virtual Storage

/ESA Enterprise Systems ArchitectureESA/390

Processors :

ES/9000, ES/3090-9000T

ES/3090 J Models

32 bit addressability

Virtual storage of 2GB

Increased maximum number

of channels and Devices

Virtual storage of 16 Terra

Bytes

Virtual storage of 16 Terra

Bytes

MVS/XA


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Input-Output Management

Problem: - Application should not worry about device characteristics. I/O device speed is 100 times

slower than CPU.

Solution: Let all I/O be handled by a specialized system-I/O Subsystem

2) I/O operation

P1

P2

P3

P1

Virtual Memory

Real Memory

File

Auxiliary Device

swapped out

swapped in I/O

Subsystem

OS

How is to be done is decided byI/O subsystem

Tells What to do

P2


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5.5 SYSTEM 370 I/O ARCHITECTURE

Channel 0

Channel 1

Channel 2

Channel 3

Channel 4

Channel 5

Channel 6

Channel 7

Main

Storage

CP

U


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STORAGE

CP CP

Channels

Devices

Channels

Provide paths between the processor & I/O devices

3090 processors can have a maximum of128 channels

A channel itself is a computer & executes I/O instructions called channel commands

I/O devices are connected to channels through an intermediate device called Control Unit.

Each channel can have up to 8 control units.

Control Unit

These are DASD units, can be connected to common control unit, and called String Controller.

String Controller can be connected to a channel directly or indirectly

A control unit called Storage Control connects string controllers to a channel.


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6 KEY TERMINOLOGY

6.1 CACHE MEMORY

High speed memory buffer (faster than main memory)

Operates between CPU and main memory

Used to store frequently accessed storage locations (instructions)

Usually available on all processors

6.2 CHANNELS

Device Management Concept - Unique to IBM

Provides access path between CPU and I/O devices (DMA)

Up to eight control units can be connected to one channel

Up to eight I/O devices can be connected to one control unit

A channel is a small computer in itself with a set of instructions (Channel commands)

Channel controls the I/O device operations independent of CPU

Cannel processing can overlap CPU processing - improved performance

6.3 CHANNEL - I/O DEVICE CONNECTIVITY

Parallel architecture i.e. all bits of a byte are transmitted simultaneously Information transfer is in unit of two bytes

Sixteen data wires and additional control wires are required

Maximum length of 120 meters (400 feet)

Data speed of 4.5mbps

Use of copper results in heavy, expensive cabling

6.4 I/O DEVICES

Unit Record Devices - Each record is a single physical unit

Card Devices (now obsolete): Readers / Punches / Reader and Punches Printer

Impact Printers - 600 to 2000 LPM

Non-Impact Printers - 3800 sub-system, 20,000 LPM

Built-in control units for each device

Directly attached to channel

Magnetic Tape

High volume storage


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Sequential processing

Normally used as back-up device

Also used for physical transfer of data

4 to 8 tape drives are connected to one control unit

DASD - Direct Access Storage Device

IBMs official name for Disk Non-removable - offers better reliability and are faster

Volume is a specific unit of storage. E.g. Disk pack or DASD, Tape

A group of DASDs of same type are connected together to form a String and are connected to a

string controller

Multiple string controller are connected to a storage controller

Storage controller is connected to channel

DASD unit

channelconnection

storage control

string controller1

string controller1

(1 - 128)

(1 - 8)

32

32

6.5 DATA COMMUNICATION NETWORK

Allows local and remote terminals access to the computer systems.

Components of data communication Host Computer - System/370 processor

Communications Controller - Attached to the channel

Devices (terminals and printers) are connected to the terminal controller (also known as

cluster controller)

Terminal controller is connected to communications controller

Terminal Controller managing Local terminals / printers can be connected directly to the channel

Modems and telecommunication lines (telephone line, Satellite Link)

Remote terminals / printers are connected to terminal controller (at local site)


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Terminal controller is connected to modem

Modem is connected to telecommunications line

At the receiving end telecommunications line is connected to modem

Modem is connected to communication controller

3270 Information Display System

Sub-system of terminals, printers and controllers connected to Host computer

Locally through communications controller or directly to channel

Remotely through communications controller, modem and telecommunications line

A typical 3270 terminal controller (3274) controls up to 32 terminals / printers

Emulator programs (Shine Link, Erma Link) allow computers (typically PCs) to mimic 3270

devices

These are useful since they allow upload / download of data between MF and PC

6.6 DATA COMMUNICATION EQUIPMENT

Data Communication equipment lets an installation create a data communication network that lets users

at local terminals & remote terminals to access computer system


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System/370 processor

channel

Host System

communication controller

modem modem

modem

terminal controller

terminalprinter

modem

terminal controller

terminalprinter

TelecommunicationLines

Remote System Remote System


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At the center of the network is the host system, a system/370 processor

The control unit that attaches to the host systems channels is called a communication controller

It manages the communication function

Necessary to connect remote terminal system

Via modems and telecommunication lines

A modem is a device that translates digital signals from the computer equipment at the sending end into

audio signal that are transmitted over a telecommunication line, which can be telephone line, a satellite

link or some other type of connection. At the receiving end of the line, another modem converts those

audio signals back into digital signal.


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7 TYPICAL MAINFRAME CONFIGURATION

With a variety of IBM Mainframe Processors and I/O devices, we can have a number of Mainframe

configurations. So one Mainframe configuration is different from the other.

7.1 A SMALL MAINFRAME CONFIGURATION

3420 Tape Drives (4) 3350 DASDs (24)

4381 Processor 8M

3279 Operator

Consoles (4)

Local 3270 System

Modems (3)

Remote 3270 Systems

3211 Printers

(2)


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Multiple Virtual Storage

MVS uses real storage and areas of DASD storage, called page-data sets, in combination to

simulate several virtual storage address spaces

Each address space provides an entire 16M range of addresses (2GB if XA is used)

As a result, to refer to a particular byte of Virtual Storage under MVS, we need to know two

things: (1) the address, which identifies a specific byte of storage within a 16M or 2GB address

space, and (2) the address space to which the address applies

When multiple virtual storages are used, the total amount of virtual storage that can be

simulated is almost limitless because MVS can create an almost unlimited number of address

spaces

However the size of an address (24 bits or 31 bits) still limits the size of each address space to

16MB or 2GB and also various factors such as the speed of the processor and the amount of

real storage installed effectively limit the number of address spaces that can be provided

A CPU can access only one address space at a time

When CPU is accessing instructions and data from a particular address space, that address

space is said to be in control of the CPU. So the program in that address space will continue to

execute until MVS intervenes and places the CPU under the control of another address space

Multiple Virtual Storage is how MVS implements multiprogramming. Each batch or time-sharing

user is given a separate address space. So each job or user can access up to 16M or 2GB of

virtual storage independent of any other job or user on the system


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PAGING

The total amount of virtual storage that can be used under MVS is almost unlimited. As a

result, the amount of real storage present on a particular machine is nearly always less than

the amount of virtual storage being used

To provide for the larger amount of virtual storage MVS treats DASD storage as an

extension of real storage

MVS divides virtual storage into 4K sections called pages

Data is transferred between real and DASD storage one page at a time

As a result, real storage is divided into 4K sections called page frames, each of which can

hold one page of virtual storage

Similarly, the DASD areas used for virtual storage, called page data sets, are divided into 4Kpage slots, each of which holds one page of virtual storage

When a program refers to a storage location that isnt in real storage, a page fault occurs.

When there is a page fault, MVS locates the page that contains the needed data on DASD

and transfers it into real storage. This operation is called a page-in

Sometimes the new page can overlay data in a real storage page frame

In other cases, data in a page frame has to be moved to a page data set to make room for

the new page. This is called page-out

So the process of bringing a new page into real storage is called paging

At any given moment, page frames in real storage contain pages from more than one

address space

MVS keeps track of what pages are in what page frames by maintaining tables that reflects

the status of real storage and of each address space. The real storage frames that contain

those tables cannot be paged out; they must always remain in real storage as long as their

associated address spaces are active

Swapping

Depending on the amount of real storage a system has and the types of jobs it is processing,

MVS can efficiently multiprogram only a certain number of jobs at once

So using a process called swapping, MVS periodically transfers entire address spaces in and

out of virtual storage, so they are temporarily unavailable for processing


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7.6 VIRTUAL STORAGE LAYOUT

Local System QueueArea (LSQA)

Scheduler Work Area

User Region

System

System Queue

(SQA)

Pageable Link Pack(PLPA)

Common Service(CSA)

Users Private

Space

Nucleus

CommonArea

PrivateArea

SystemArea

Each Virtual Storage Address Space consists of a System Area, a Private Area and a Common Area.

System Area

It contains the nucleus load module, page frame table entries. Data blocks for system libraries

and so many other things

Nucleus and other contents of the System Area make up the resident part of the MVS system

control program

Its contents are mapped one for one into real storage frames at initialization time.

The size of System Area does not change once it is initialized

Common Area

It contains parts of the system control program, control blocks, tables and data areas


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Private Area

The Private Area is made up of: Scheduler Work Area (SWA) System Region User Region

The user region is the space within Private Area that is available for running the users program

Scheduler Work Area

SWA contain control blocks that exist from task initiation to task termination

The information in SWA is created when a job is interpreted and used during job initiation and

execution

It is pageable and swappable


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8 MVS FUNCTIONS

8.1 DATA MANAGEMENT OVERVIEW

Anything that needs to be stored and accessed on user request is a Data for MVS

8.2 TYPES OF DATA

Business Data

Database Indexed Files Flat Files

Application Components

Source Programs Executable Programs Screen Definitions Record Layout Definitions Command File Scripts

MVS (System Data)

O/S program User Information (ID, Password, Profile) Access Permissions

Temporary Data

O/S Built Data (e.g. task queues, segment table, page table) Spooled Output Work Files for Sort

8.3 DATASET ORGANIZATION

Dataset organization fall into two categories under MVS: VSAM and NON-VSAM

Non-VSAM provides four basic ways of organizing data stored in datasets

Physical Sequential

Indexed Sequential

Direct


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Partitioned

VSAM provides four basic ways of organizing data stored in datasets

Entry Sequence Dataset - ESDS

Key Sequence Dataset - KSDS

Relative Record Dataset - RRDS

Linear Dataset - LDS

8.4 NON-VSAM DATASETS ORGANIZATION

Physical Sequential

Records are stored one after another in consecutive sequence

Can reside on just any type of I/O devices Appropriate when files records dont have to be retrieved at random

Indexed Sequential

Includes an index, which relates key field values to the location of their corresponding data

records

Direct

Permits random access of records

It doesnt use an index

To access record, the disk location address (By hashing) of that record to be specified

Partitioned

Consists of one or more members

Each of these members can be processed, as if it were a separate physical sequential file.

Names of members in a Partitioned dataset (PDS) is stored in a directory

8.5 DATASET ORGANIZATION

Partitioned Data Set - Salient Features

Commonly referred as PDS

Also known as Library

Used to store application components

PDS is divided into one or many members


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Member name can be up to 8 characters long

There is no extension for member

Each member can be processed as an individual unit

Entire PDS can be processed as one unit

Each PDS contains a directory

Directory has an entry for each member in a PDS

- PDS Examples:

PAYROLL.TEST.SOURCE, PAYROLL.PROD.SOURCE,

INV.TEST.LOADLIB

Normally consists of 3 qualifiers called as

- PROJECT

- GROUP

- TYPE

Personal PDS start with high level qualifier as User ID

E.g. DA00T23.NEW.SOURCE

Member Name Examples

PAB0017, PAB0105, PAC0021 etc.


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First character of the qualifier must be alpha or national character

Last character of data set must not be .

First qualifier is called high-level qualifier

High-level qualifier has special significance

E.g. Data Set name PAYROLL.P9710.TRAN

Has three qualifiers

High-level qualifier is PAYROLL

Total length is 18

Dataset Tracking

Data Set Tracking Mechanisms

Label

Catalog

Label

DASD Label

Each DASD is labeled; called Volume Label (VOL1 label) DASD label contains Volume Serial Number and address of the VTOC file

Volume Serial Number

Each DASD is identified by a unique number, Volume Serial Number vol-ser

Vol Ser must be specified for accessing the Data Set (which is not cataloged)

Data Set Label

Each data set is a label record called File label or Data Set Control Block (DSCB) DSCB describes data sets name, its DASD location and other details

VTOC

VTOC - Volume Table Of Contents is a special file for each DASD VTOC contains the file labels for all data sets on the volume

8.9 MVS DATASETS

Label Processing

When a dataset is stored on disk or tape, MVS identifies it with special records called labels

There are 2 types of DASD labels: Volume, File Label

All DASD volumes must contain a volume label, often called a VOL1 label. This label is always

in the same place on a disk volume: the 3rd record of track zeros in cylinder zero

Volume label has 2 important functions


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It identifies the volume by providing a volume serial no: VOL-SER. Every DASD volume must

have a unique six-characters VOL=SER

It contains the disk address of the VTOC

The VTOC (Volume Table of Contents) is a special file that contains the file labels for the

datasets on the volume

VTOC

VOL 1 Label

Format-4VTOC

Format-1FileA

Format-1File-B

Format-1File-C

Format-3File-B

Format-5Free Extents

Free Extents

File-A

File-B

File-C

Free Extent

File-B

Free Extent

Catalog

Obviates the need of specifying VOL SER and UNIT for the data set

Catalog Types

CVOL

VSAM

ICF (Integrated Cataloging Facility)

Catalog Features

Each MVS has only one Master Catalog and also functions as system catalog

Master Catalog is used by MVS for system data sets

User Catalog is used for user data sets


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There can be multiple User Catalogs

Master Catalog contains one entry of each User Catalog

- VSAM data sets must be Cataloged

- Non-VSAM Data Sets may or may not be cataloged

- An Alias can be created for a Catalog

Usually, the high-level qualifier of a data set is same as the catalog name or catalog alias name

Multiple data sets can be cataloged in single user catalog

Alias helps to catalog data sets with different high-level qualifiers to be cataloged in a single

user catalog

Catalog Name VCAT.MPS800 Alias MMA2 MMA1

Data Set Name MMA2.CUSTOMER.MASTERMMA1.CUSTOMER.TRAN

8.10DATA MANAGEMENT

Data Management Functions (for Non-PDS)

Allocate

Process

- Add Records

- Modify Records

- Delete Records

De-allocate (delete)

Copy

Rename

Catalog

Additional Functions for PDS

Compress

Member Management

Create, Modify, Delete, Copy, Rename


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How Data Management is achieved?

Interactively using MVS Commands

Executing MVS Utility Programs (batch mode)

Through Application Programs

- On-line Processing

- Batch Processing

MVS Concepts

8.11HOW DATASETS ARE ACCESSED?

Generally dataset goes through three phases when handled through program:

Allocation

Processing De-allocation

Allocation

The process of locating an existing dataset or space for a new dataset and preparing the system

control block needed to use the dataset is called Allocation

Allocation occurs at 3 levels

Unit is selected and allocated e.g. SYSALLDA-DASD, TAPE

Volume is allocated

Dataset on that volume is allocated

Processing

Processing involves 3 steps

Opening datasets

Processing I/O

Closing datasets

De-allocation

Each file is automatically de-allocated when step terminates. While de-allocating, disposition of dataset

can be decided, whether you want to retain the file or should be deleted.


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9 JOB MANAGEMENT OVERVIEW

9.1 WHAT IS A JOB?

Simply put, job is an execution of one or more related programs in sequence

E.g. 1

A job of creating an executable module (load module) from a source program consists of compilation

and link editing a program.

Job - Salient Points

Executed in a background mode

Job details are specified using some command language

9.2 JOB MANAGEMENT FUNCTIONS

Receive the job into operating system

Schedule the job for processing by O/S

Execute the Job

Process the output

9.3 STAGES OF JOB

1. Job Preparation

User keys-in commands using Editor

Save as a member in PDS

2. Job Scheduling

Initiated using TSO SUBMIT command Not necessarily on FIFO basis

Prioritization is implemented using concept of class and priority code

3. Job Execution

4. End of execution (normal, erroneous)

Intimate the user


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Job log management

Job output management

Printer output

Data set output

Erroneous Termination of job Type of execution errors

Incorrect commands (command syntax errors)

Required resources (Data Sets, Program Library, Program Load Module) not available

Violation of access permissions for data sets, program load module etc

Mismatch in data set status; as required by job and as it actually exists e.g. a create is issued for

a data set while data set which already exists

Program errors

Mismatch for Data set - Between program definition and actual characteristics

Infinite loop

Data Type mismatch - numeric variable contains non-numeric data

Any abnormal termination of program is called Abend

9.4 JOB MANAGEMENT

Definitions

JOB - Is an execution of one or more related programs in sequence

JOB STEP - Each program to be executed by a Job is called a job step

JCL (Job Control Language) - Is a set of control statements that provide the specifications necessary to

process a job

JES (Job Entry Subsystem):

Meant for job entry into system, also for job returning after completion

Shares the load on the operating system

Takes care of all inputs and outputs

Do simple basic syntax checking

Resource Initialization

Creation of address space

It is also known as Job Scheduler

Classified into

JES2-design for uni-processor environment

JES3-design for multiprocessing environment (Decided at the time of system initialization)


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If two or more jobs have same class & priority, they are executed in the order in which they are

submitted.

How Job Is Executed

Once an initiator has selected job for execution, it invokes a program called the interpreter. The

interpreter's job is to examine the job information passed to it by JES and create a series of controlblocks in the SWA, a part of the address spaces private area. Among other things, these control blocks

describes all of the datasets the job needs. Now initiator goes through 3 phases for each step of job.

Allocation (required resources are allocated). Processing (region is created and program is loaded and

executed). De-allocation (resources are released). This continues until there are no more job steps to

process. This continues until there are no more job steps to process. Then, the initiator releases the job

and searches the spool again for another job from the proper class to execute. As a users program to

execute, it can retrieve data that was included as part of job stream and stores in the JES spool

JES SPOOL INITIATOR

Job

JCL SYSIN

SYSOUT QUEUE O/P DATA INTERPRETORPROGRAMEXECUTIONSYSOUT

How The Jobs Output Is Processed

Like Jobs, SYSOUT data is assigned an output class that determines how the output will be handled

Common O/P classes are:

A - Printer

B - Card Punch O/P

X - Held O/P

[Held O/P stays on the sysout queue indefinitely; Usually, O/P is held so that it can be examined

from a TSO terminal]

How A Job Is Purged


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After the jobs output has been processed, the job is purged from the system, i.e. JES spool

space, the job used, is freed so it can be used by other jobs and any JES control blocks

associated with the job are deleted

Once a job has been purged, JES no longer knows of its existence


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10 DATASET ALLOCATION AND JOB STEP EXECUTION

SWA

control block

System Region

Allocation

Initiator

SWA

control block

System Region

Initiator

User Program

SWAcontrol block

System Region

Interpreter

Initiator

After initiator selects a job forexecution, it invokes theinterpreter, which builds therequired control blocks in theaddress spaces SWA.

For each job step, the initiatorinvokes allocation routines toallocate the units, volumes anddatasets required by the jobstep

After resource allocation, theinitiator creates a user region,loads the user program into itand transfers control to userprogram


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SWA CONTROL BLOCK

INITIATOR

SYSTEM REGION

UNALLOCATION

When the user program completes, the initiator invokes Unallocation routine to Deallocate the resources

used by the job step


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11 MVS TOOLS OVERVIEW

Tools are a set of sub-systems and facilities that;

Implement MVS functions

Are directly used by MVS user

These are essentially Software programs; system programs

Interactive Processing Tools (TSO - Time Sharing Option)

Used by the terminal user to invoke MVS facilities interactively

TSO internally treats each terminal user as a Job

Job Stream is created when terminal user logs in Each terminal user is given a separate address space

ISPF - Interactive System Productive Facility

Runs as part of TSO

Takes advantage of full screen (24 x 80) capability of 3270 terminals

Panels are provided for terminal users for issuing commands

Key Functions Implemented Using ISPF

Editor - Program Sources, Job Commands Data Management - PDS and Physical Sequential Data Set Management

Job Processing - Initiate Job, Check job log

Miscellaneous

PDF - Program Development Facility is Part of ISPF

11.1JOB MANAGEMENT TOOLS

Job Control Language (JCL)

Used to code job commands

Job Entry System (JES)

Manages the job before and after execution; receive, schedule, process output

Base Control Program (BCP)

Manages the job during execution

Simultaneous Peripheral Operations on-line (SPOOL)

Used for staging of input and output


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11.2WHY AND WHAT OF JCL?

JCL is the most dreaded word for newcomer to IBM world

Why JCL?

Since the job is executed in background, without user interaction, all information required for the

execution must be supplied in advance

JCL is used to specify this control information

The most common information supplied through JCL is:

- To whom the job belongs (which user id)?

- What is the program / utility that is to be executed?

- Where (in which library / PDS) to find the load module of the program or utility?

- Where (which DASD volume / catalog, what data set name) to find the input data files for the

program / utility?

- Where should (which DASD volume, what data set name) the output files be created?

- The printer output should be directed to which printer?

What is JCL?

Stands for Job Control Language Connotation is; set for job commands stored as a MEMBER in a PDS e.g. JCL to execute a batch

program, JCL to compile and link a COBOL program, JCL to allocate a VSAM data set, JCL toSORT and MERGE two Physical Sequential Data Sets

Thus, JCL is nothing but a set of commands

- User keys-in commands using a editor

- Saves as PDS Member e.g. PAYROLL.TEST.JCL(PROG1JCL)

Good grasp of JCL is a must to be a versatile IBM programmer

11.3JES - JOB ENTRY SYSTEM

Introduction


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Two versions of JES; JES2/JES3

- JES2 is primarily for single processor systems

- JES3 is for multiple processor systems

Each MVS system uses either JES2 or JES3

JES3 has additional scheduler functions than JES2 (e.g. schedule job at specific time of the day,

interdependent job scheduling)

11.4MVS TOOLS OVERVIEW

How Job Enters the System?

Job can enter the system from local or remote card readers (now obsolete) By starting a cataloged JCL procedure (e.g. when user logs in, a predefined set of commands

are executed as a batch job. These commands are stored as cataloged JCL procedure)

By interactive users thru SUBMIT command. Users can create a PDS member in which

commands are specified. On issuing SUBMIT command these are executed as a job.

We will focus on third approach

Input

On SUBMIT, internal reader reads the JCL and creates an input stream

JES2 reads the input stream, assigns a Job Number and places input stream in SPOOL data set(a message is sent to TSO user about the job number)

Job is put in the conversion queue

Conversion

Converter program analyzes JCL statements

Converts into converter / interpreter text

Checks for Syntax errors

- If any error, Job is queued for output processing

- If no error, Job is queued for processing

Processing

Selection based on job class and priority

Selected job is passed to Initiator

Initiator invokes Interpreter


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Interpreter builds control blocks from converter / interpreter text in a Scheduler Work Area

(SWA)

- SWA is part of address spaces private area

- Control blacks describe the data sets required by the job

Initiator allocates resources required by the Job

- Initiator starts the program to be executed

- Builds the user region

- Loads the program in the user region

- Transfers control to the program

On completion of the program execution, initiator de-allocates the resources

The process of allocation / execution and de-allocation is repeated for each job step


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Initiator Characteristics

Each initiator can handle one job at a time

There can be multiple initiators

Each initiator has a job class associated with it

System Operators can control the number of initiators and the class/es associated with each

initiatorInput Data

Input data to the users program can be specified in the job

Called in-stream data or SYSIN data

SYSIN data is read and stored in JES spool

SYSIN data is treated like a data coming from card reader

Output

Management of System Messages, User Data Sets that need to be Printed / Punched

Organized by output class and device set-up requirements User s program can produce output data that is stored in a JES spool; called SYSOUT data

Each SYSOUT data is assigned an output class

Output class indicates the printer selection

Held Output

- Special class (usually Z) is assigned to hold the output

- Held output remains in the SYSOUT indefinitely

- Usually used to verify before printing

- User can change the class and thus release the held output

Hard-Copy

Local or remote processing

Device Selection

Queue the output for print /punch

Purge

Release SPOOL and Job Queue space

Intimate TSO user about job completion

Job Output

Output is produced at each stage job processing

Includes output produced by;


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- JES

- MVS

- Users program where SYSOUT is allocated as output device

Job output is available to user (you can see it dynamically) It can be viewed using ISPF

11.5COMPONENTS OF JOB OUTPUT

Component 1- Separator Page

First and last page of job output

Inserted by JES

Helps operator the segregate the job outputs when directed to printer

Component 2 part I Job Log

Messages produced by JES

Also displayed on operators console

If the job Abends, error messages are logged in Job Log

Component 2 part II Job Statistics

Summary information of system resources used by the job e.g.;

Number of JCL cards

Spool usage

Execution time

Component 3 - JCL Listing

List of JCL that was processed for the job

Should be same as what user has created

Component 4 - Message Log

Messages regarding job execution

Messages produced by MVS Includes details of

Resource Allocation

Program Execution

Resource De-allocation

Consists of Message label and message text

Message label starting with IEF indicates a MVS message

Installation specific messages


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Component 5 - SYSOUT

Separate sub-component for each SYSOUT allocation

Each SYSOUT can have different characteristics e.g. class, record length etc.

11.6VTAM VIRTUAL TELECOMMUNICATIONS ACCESS METHOD

Telecommunications (TC) Access Method

Required to support terminal devices

Part of SNA System Network Architecture

Provides centralized control over all terminals attached to the system

VTAM Application programs (e.g. TSO, CICS IMS-DC) communicate with terminal devices via

VTAM


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11.7CICS CUSTOMER INFORMATION CONTROL PROGRAM (OPTIONAL

COMPONENT)

Interactive applications are developed using CICS

CICS is a VTAM application program

Works with VTAM to support on-line functions

CICS implements multi-programming within itself

Multiple programs which are part of same application are executed within CICS address space

CICS selects one program at a time for execution

CICS itself is multi-programmed by MVS along with other programs

11.8DB2 - DATABASE 2 (OPTIONAL COMPONENT)

Database Management System

Relational Implementation

11.9RACF - RESOURCE ACCESS CONTROL FACILITY

Comprehensive Security Package

Though optional used by most of the installations

Users and Resources (e.g. Data Sets) are identified to RACF Whenever user tries to access a resource the security is checked by RACF

RACF is a set of routines

Invoked as and when required

11.10SMF - SYSTEM MANAGEMENT FACILITY

Keeps track of system usage

CPU, DASD I/O, Records Printed etc.

Data collected when job is executed

Stored in a special data sets

Used for billing


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List Datasets

Print Datasets

Copy Datasets

Delete Datasets

Rename Datasets

List Catalog Entries

List VTOC Entries Use AMS Services

Program Development functions

Create program.

Edit program.

Compile program.

Link edit a program.

View output.

Route output to a printer

Batch job functions

Submit Jobs

Monitor job

View output

Route output

Help

Help on TSO commands can be obtained by typing, HELP at the READY prompt.


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12 INTERACTIVE SYSTEM PRODUCTIVITY FACILITY (ISPF)

Access to ISPF is gained by Keying ISPF at the READY prompt

This is done as default in the auto executed Clist at startup When this is entered you get the Primary Options Menu

12.1PRIMARY OPTIONS MENU

----------------------- ISPF/PDF PRIMARY OPTION MENU ------------------------

OPTION ===> pfshow USERID - DA0034T

0 ISPF PARMS - Specify terminal and user parameters TIME - 06:58

1 BROWSE - Display source data or output listings TERMINAL - 32782 EDIT - Create or change source data PF KEYS - 12

3 UTILITIES - Perform utility functions

4 FOREGROUND - Invoke language processors in foreground

5 BATCH - Submit job for language processing

6 COMMAND - Enter TSO Command, CLIST, or REXX exec

7 DIALOG TEST - Perform dialog testing

8 LM UTILITIES - Perform library administrator utility functions

9 IBM PRODUCTS - Additional IBM program development products

10 SCLM - Software Configuration and Library Manager

C CHANGES - Display summary of changes for this release

T TUTORIAL - Display information about ISPF/PDF

X EXIT - Terminate ISPF using log and list defaultsD DATACENTER - Perform Datacenter Defined Functions

S SDSF - Spool Display and Search Facility

U USER - Perform User Defined Functions

F1=HELP F2=SPLIT F3=END F4=RETURN F5=RFIND F6=RCHANGE

F7=UP F8=DOWN F9=SWAP F10=LEFT F11=RIGHT F12=RETRIEVE


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PA/PF Key Map

PF1 ===> HELP Enter the Tutorial

PF2 ===> SPLIT Enter Split Screen Mode

PF3 ===> END Terminate the current operation

PF4 ===> RETURN Return to primary options menu

PF5 ===> RFIND Repeat find

PF6 ===> RCHANGE Repeat Change

PF7 ===> UP Move screen window up

PF8 ===> DOWN Move screen window down

PF9 ===> SWAP Activate the other logical screen in split screen mode

PF10 ===> LEFT Scroll screen left

PF11 ===> RIGHT Scroll screen right

PF12 ===> RETRIEVE Retrieve last command

PA1 ===> ATTENTION Interrupt Current operation

PA2 ==> RESHOW Redisplay the current screen

PF1 - PF12 Keys may be duplicated from PF13 to PF24 in 24 key mode.

Split Screen Mode and Tutorial (Help)

Entered by keying SPLIT on the command line

Or by positioning the cursor where required and pressing PF2

Context Sensitive help can be accessed by typing help on the command line or through the PF1 key

List and Log files

Some ISPF commands generate outputs. Printed output like this is collected and stored in a special

dataset call list dataset

Whether the list dataset is to be retained, printed and/or deleted can be specified as a default in the

setup panels

The ISPF operations done are recorded in a Log dataset. The disposition can be specified in the

defaults panel

User Profile

ISPF maintains a user profile

This profile contains default values of various entry panels.

Exiting ISPF


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12.5 BROWSE COMMANDS

Cols - for displaying Columns

Scroll up, down, left right with PF7, PF8, PF10 and PF11 respectively. Set Scroll amount to CRSR, HALF, PAGE, n lines, max, DATA

Scroll by n lines, to top or bottom

Define/LOCATE {line number}/label.

FIND string {NEXT/PREV/FIRST/LAST/ALL}.

PF5 for repeat find and use of &.

Use of PF12 to recall last command.

Terminate Browse with PF3 Key.

FIND string {NEXT/PREV/FIRST/LAST/ALL} {CHAR/PREFIX/SUFFIX/WORD} col-1 col-2

Column limitation search

T text - for case insensitive search

X hex-string for a hex search

12.6 EDITING DATASETS (OPTION 2)

The Primary Editor entry is similar to that for Browse as regards concatenating datasets and dataset

selection

Labels can be defined as in browse but may be entered as line commands

Error messages may be removed by typing RESET on the command line

12.7 STANDARD EDITING COMMANDS

I/In Insert 1 or n lines.

D(n) Delete line or n lines.

DD Delete the block marked by the 2 DD line commands.

R(n) Repeat 1 or n lines.

RR Repeat the block marked by the 2 RR line commands.

C(n) Copy 1 or n lines.

CC Copy the block marked between the 2 CC line commands.

M(n) Move 1 or n lines.MM Move the block marked between the 2 CC line commands.

A(n) Copy or Move lines 1 or n times after this l ine.

B(n) Copy or Move lines 1 or n times before this line.

Creating datasets and exiting editor


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To create a new member specify non-existent member name in the current PDS.

You can quit the editor without saving changes by the CANCEL command.

You can update the dataset with the save command

You can exit with implicit save with the END command or PF3 key.

12.8 EDIT PROFILES

Edit profiles control editing options

Normally editing a new dataset uses the default profile - the dataset type

To display the edit profile type PROFILE on the command line in the editor

To remove it from the screen type RESET.

This gives you a display as follows.


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EDIT ---- DA0034T.TRG.JCL(JCL1) - 01.27 ---------------------- COLUMNS 001 072

COMMAND ===> SCROLL ===> CSR

****** ***************************** TOP OF DATA ******************************

=PROF> ....STD (FIXED - 150)....RECOVERY OFF....NUMBER ON STD..................

=PROF> ....CAPS ON....HEX OFF....NULLS ON STD....TABS ON STD....SETUNDO OFF....

=PROF> ....AUTOSAVE ON....AUTONUM OFF....AUTOLIST OFF....STATS ON..............

=PROF> ....PROFILE UNLOCK....IMACRO NONE....PACK OFF....NOTE ON................

=BNDS>

=COLS> ----+----1----+----2----+----3----+----4----+----5----+----6----+----7--

000100 //DA0034TA JOB LA2719,'PARAG',NOTIFY=DA0034T,

000200 // CLASS=A,MSGCLASS=X

000300 //*

000400 //COBRUN EXEC PGM=PROG11

000500 //STEPLIB DD DSN=DA0034T.TRG.LNK,DISP=SHR

000510 //*STEPLIB DD DSN=DA0034T.TRG.COBOL2,DISP=SHR

000600 //INVMAS DD DSN=DA0034T.TRG.INVMAS,DISP=SHR

000700 //OP1 DD SYSOUT=*

000710 //*OP1 DD DSN=DA0034T.TRG.EXE7,DISP=(NEW,CATLG,CATLG),

12.9PROFILE SETTINGS

To switch to a different profile key profile

To lock a profile, at the command line key PROFILE LOCK

Any changes made to the locked profile are not saved permanently. Caps, number Pack and STATS modes are set each time you begin an edit session

To define tab stops. Key TABS on the command line and place @ on the tabs line one character

before where you would like a tab stop. On the command line, Key TABS ON/OFF

If you omit the tabbing character hardware tabbing is assumed.

Line control Commands

Nonumber/NUM OFF turns off line numbering

NUM ON turns on line numbering

AUTONUM resequence line numbers on save

RENUM resequence line numbers

NUM ON COBOL checks for valid COBOL numbering NUM ON STD checks for standard line numbering

UNNUM removes line numbering.

12.10EDIT MODES


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Data shifts

Does not drop blank characters

Does not combine words by drooping spaces

Does not delete spaces within apostrophes

COPY [member] [AFTER/BEFORE label]

MOVE [member] [AFTER/BEFORE label] CREATE [member] [range]

REPLACE [member] [range]

Edit member-name to edit recursively

12.13 UTILITIES MENU

Option 3

------------------------- UTILITY SELECTION MENU ----------------------------

OPTION ===>

1 LIBRARY - Compress or print data set. Print index listing.

Print, rename, delete, browse, or edit members

2 DATASET - Allocate, rename, delete, catalog, uncatalog, or

display information of an entire data set

3 MOVE/COPY - Move, copy, or promote members or data sets

4 DSLIST - Print or display (to process) list of data set names

Print or display VTOC information

5 RESET - Reset statistics for members of ISPF library

6 HARDCOPY - Initiate hardcopy output

8 OUTLIST - Display, delete, or print held job output9 COMMANDS - Create/change an application command table

10 CONVERT - Convert old format menus/messages to new format

11 FORMAT - Format definition for formatted data Edit/Browse

12 SUPERC - Compare data sets (Standard Dialog)

13 SUPERCE - Compare data sets and Search-for strings (Extended Dialog)

14 SEARCH-FOR - Search data sets for strings of data (Standard Dialog)


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12.14 LIBRARY UTILITY

Option 3.1

---------------------------- LIBRARY UTILITY --------------------------------

OPTION ===>

blank - Display member list B - Browse member

C - Compress data set P - Print member

X - Print index listing R - Rename member

L - Print entire data set D - Delete member

I - Data set information E - Edit member

S - Data set information (short)

ISPF LIBRARY:

PROJECT ===> DA0034T

GROUP ===> TRG ===> ===> ===>

TYPE ===> JCL

MEMBER ===> (If "P", "R", "D", "B", "E" or blank selected)NEWNAME ===> (If "R" selected)

OTHER PARTITIONED OR SEQUENTIAL DATA SET:

DATA SET NAME ===>

VOLUME SERIAL ===> (If not cataloged)

DATA SET PASSWORD ===> (If password protected)


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12.15 DATASET UTILITY

Option 3.2

---------------------------- DATA SET UTILITY -------------------------------

OPTION ===> A

A - Allocate new data set C - Catalog data set

R - Rename entire data set U - Uncatalog data set

D - Delete entire data set S - Data set information (short)

blank - Data set information M - Enhanced data set allocation

ISPF LIBRARY:


GROUP ===> TRGTYPE ===> JCL


DATA SET NAME ===>

VOLUME SERIAL ===> (If not cataloged, required for option "C")

DATA SET PASSWORD ===> (If password protected)

12.16 NEW DATASET ALLOCATION

Option 3.2.A

------------------------ ALLOCATE NEW DATA SET ------------------------------

COMMAND ===>

DATA SET NAME: DA0034T.TRG.JCLS

VOLUME SERIAL ===> BS3008 (Blank for authorized default volume)

GENERIC UNIT ===> (Generic group name or unit address)

SPACE UNITS ===> BLOCK (BLKS, TRKS, or CYLS) PRIMARY QUANTITY ===> 26 (In above units)

SECONDARY QUANTITY ===> 12 (In above units)

DIRECTORY BLOCKS ===> 0 (Zero for sequential data set)

RECORD FORMAT ===> FB

RECORD LENGTH ===> 150

BLOCK SIZE ===> 1500

EXPIRATION DATE ===> (YY/MM/DD, YYYY/MM/DD

YY.DDD, YYYY.DDD in Julian form DDDD for retention period


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in days or blank)

( * Only one of these fields may be specified)

12.17 RENAMING DATASET

Option 3.2.R

---------------------------- RENAME DATA SET --------------------------------

COMMAND ===>

DATA SET NAME: DA0034T.TRG.JCL

VOLUME: BS3008

ENTER NEW NAME BELOW: (The data set will be recataloged.)

ISPF LIBRARY:


GROUP ===> TRG

TYPE ===> JCL


DATA SET NAME ===>

12.18DATASET INFORMATION

Option 3.2.s

-------------------------- DATA SET INFORMATION -----------------------------

COMMAND ===>


GENERAL DATA: CURRENT ALLOCATION:

Management class: MCSTANDS Allocated blocks: 26

Storage class: SCNORM Allocated extents: 1

Volume: BS3008 Maximum dir. blocks: 1

Device type: 3390

Data class:

Organization: PO CURRENT UTILIZATION:

Record format: FB Used blocks: 11

Record length: 150 Used extents: 1

Block size: 1500 Used dir. blocks: 1


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1st extent blocks: 26 Number of members: 5

Secondary blocks: 12

Data set name type: PDS

Creation date: 1996/08/08

Expiration date: ***NONE***

12.19 ALLOCATING DATASETS

------------------------ ALLOCATE NEW DATA SET ------------------------------

COMMAND ===>


MANAGEMENT CLASS ===> MCSTANDS (Blank for default management class)

STORAGE CLASS ===> SCNORM (Blank for default storage class)VOLUME SERIAL ===> (Blank for authorized default volume)

DATA CLASS ===> (Blank for default data class)

SPACE UNITS ===> BLOCK (BLKS, TRKS, CYLS, KB, MB or BYTES)

PRIMARY QUANTITY ===> 26 (In above units)

SECONDARY QUANTITY ===> 12 (In above units)

DIRECTORY BLOCKS ===> 1 (Zero for sequential data set) *

RECORD FORMAT ===> FB

RECORD LENGTH ===> 150

BLOCK SIZE ===> 1500

DATA SET NAME TYPE ===> PDS (LIBRARY, PDS, or blank) *

EXPIRATION DATE ===> (YY/MM/DD, YYYY/MM/DD

YY.DDD, YYYY.DDD in Julian formDDDD for retention period in days

or blank)

(* Specifying LIBRARY may override zero directory block)

Documents

l1 Mfcics Mvs Student Guide