My Background: I work with a CM system that is used to support multi-project COBOL and other language compilations, so I am familiar with many of the problems involved in upgrading from one version of a language to another.

This book discusses the problems and issues involved when upgrading COBOL programs on IBM mainframes. There is no discussion of the various implementations of COBOL on platforms other than these. Given these constraints I would expect the target readership and usefulness of this book to be limited to those working with IBM mainframes. This is one of the reasons that I have reservations about recommending it. My second reservation is about the CD-ROM - see later.

Like other books published during the late '90s there is some discussion in the introduction of the 'Y2K' problem and actions to resolve it, but this does not take up a great deal of space even though it is now redundant.

The introduction also covers the background and experience of the authors who have been involved in upgrading 6000+ programs to newer versions of COBOL, using a number of different methods.

The three main parts of the book discuss how to upgrade from one version of COBOL to another using:

• manual approach;
• a tool-based approach;
• outsourcing.

The COBOL versions considered are: OS/VS COBOL, VS COBOL II and COBOL for MVS VM, the latter being originally known as COBOL/370.

Each part discusses how each language element needs to be updated in order to satisfy the target compiler. For example there are tables listing all of the COBOL reserved words in each of the compiler implementations with comments explaining how to deal with the problems that can arise. Each of these sections would be useful to anyone considering a migration from one compiler version to another, although I found that the font and layout used made these chapters a tiring to read at times. Still I think if the book is used purely as a reference then this factor is less important.

The CD contains four files, 872KB in total, one is 'readme.txt' containing only the titles of a number of tables or sections in the main text. The remaining files are 'Word 97 .doc', '.rtf' and '.txt' versions of the contents of the sections mentioned in the 'readme.txt'. It seems odd to provide a CD just to contain these items when a) they're in the book anyway; b) a floppy would have been adequate; c) a www page would be easier for many and d) the book cover says: On the enclosed CD-ROM you'll find:

• Handy information on using IBM's CCCA conversion software
• Programs from the book and additional compile procs'

Although the CD does contain these items no additional information is included and the reader's expectation may, like mine, have been greater. I expected the CD to contain additional information that isn't in the book and, preferably, in an easily browsed format, say html, - an opportunity to 'add value' was missed here.

The book clearly intends to provide assistance to conversion projects and it does so on a point by point basis, taking a step by step approach within each of the parts. In this way it is a good reference for projects facing this type of problem. I have not read through every single paragraph because I do not believe that this is the way that most people will use it.

Should you buy it? Well only if you're involved in conversion and then only for use by the project team, for an individual it would be easier to obtain a copy from the library when needed. My opinion would probably change if added value was provided on the CD.

Recommended with reservations.