Murach's OS/390 and Z/OS JCL (Murach: Training & Reference) [Paperback]

I picked up Murach's OS/390 and z/OS JCL, and it does an excellent job
of describing the architecture and nomenclature of mainframe
systems. It presumes that you nothing about mainframe systems. To get
started, you should know that MVS, OS/390 and z/OS are all basically
interchangeable terms for the mainframe operating system (quibbling
over these terms would be like quibbling over whether Linux were a
Unix operating system). JCL is "job control language" and is the
original front end for mainframe systems when punch cards were their
primary external interface. There are now a number of easier
interfaces that allow you submit JCL to a mainframe.

Anyhow, this book has been a very valuable guide to me for
understanding the basics of mainframe systems and giving me the
information i need in order to analogies between it and other systems
that i know better. For example, i now know that a data set is kind of
like a file, a directory, or a filesystem, depending on how you look
at it. And i have some sense of what CICS and VSAM are.

I was also surprised to see such a modern book format on a topic that
i'm prone to consider dated. It's a large format with the text running
on the left hand pages and examples, diagrams and summaries on the
right. The main ideas of each spread are covered three times: in the
narrative on the left, and in the examples and summary ("description")
on the right. On many pages, i found myself not turning the page until
i understood the material before me. It's a great format, and on the
strength of it alone, i've already picked up Murach's book on Java for
my technical library.

The first two chapters give a very condensed, but extremely thorough introduction and overview of IBM's mainframe environment from a hardware and operating system perspective. Since we continue to see forecasts that there will be a growing shortage of programmers for this environment, this is exactly the type of "quick start" introduction that will help bring new programmers up to speed. Chapter three gives a very quick overview of ISPF, enough to get started using ISPF to accomplish basic editing, submit jobs, and review job output.

Following the introductory section, Job Control Language is covered from the basics of statement format to how to accomplish more complex tasks - managing program execution, allocating disk and tape datasets, handling special circumstances of SYSOUT datasets, and using procedures. More advanced JCL skills, including conditional processing, job restart/recovery, creating and using generation data groups, and using the Storage Management Subsystem to allocate datasets is covered in the next section.

But this is much more than a simple text on Job Control Language. It includes a section on the basics of Virtual Storage Access Method (VSAM), along with JCL required to create and use VSAM datasets. The chapter covering Access Method Services (IDCAMS) includes just about everything an application programmer will need to know to create and manage VSAM objects. The most commonly used IBM utility programs, such as IEHMOVE, IEBCOPY, and IEBDG are explained with examples for their use. And the chapter devoted to the Sort/Merge utility covers both stand alone and internal sorts along with the most common sort control statements.

The book concludes with a couple of chapters that will provide the reader with a working knowledge of CLISTS, REXX, and UNIX System Services. With the inclusion of the information about SMS and UNIX System Services, the text is desk ready for programmers working in a z/OS environment, IBM's current version of their flagship operating system. But this book will be equally usable by programmers working on earlier versions of OS/390 and MVS. Murach's "paired page" format is easy to read for those using the text in training mode and also makes this a great choice for use as a reference tool.

I would very much recommend this book to anyone new to z/OS -- or anyone like myself who gets annoyed at how difficult it is to find out some detail that they have just forgotten.