“Mainframe” in the title of this book refers only to System/370, and “assembler” refers only to Basic Assembler Language (BAL). More precisely, they refer to PC/370, a 370 emulator that runs on PCs and accompanies the book on a floppy disk. With these understandings, the book is, as it claims to be, “an easy-to-read assembler text…emphasiz[ing] business applications.” It consists of 17 chapters: “Getting Started with PC/370,” “Defining and Moving Character Data,” “IFs in BAL: Comparing Character Fields,” “How to Structure a BAL Program,” “Data Representation,” “What’s This Stuff [the binary listing] On the Left?” “Packed Decimal Arithmetic,” “Page Break Logic,” “The Edit Instruction,” “Control Break Logic,” “More than One Input File,” “Sequential File Update,” “More Packed Decimal Arithmetic,” “Binary Arithmetic,” “Table Processing,” “More Binary Arithmetic,” and “Bit-Level Operations.” The chapters are subdivided into more than 100 sections. Four appendices complete the book.

The text is intended for a one-semester course, and Qualls says the typical student will have had three preceding semesters of related studies in Basic, programming logic, and Cobol. Clearly, the purpose is to prepare the graduate for the low-level programming job market, not to be a computer scientist. The emphasis is on certain fundamental business programming problems, involving reading and writing files, formatting printed output, and simple arithmetic. Operations and features of the assembler are introduced only as needed for these purposes. More complex activities, such as sorting, are to be performed outside the students’ programs using DOS utilities. Although the only reason given for learning assembler (other than that it provides a general background that might improve one’s Cobol programming) is to deal with the Year 2000 problem, how to do so is not covered.

The text tries to treat assembly language as much like a higher-level language as possible. It emphasizes instructions that operate memory to memory; registers are discussed only when absolutely necessary (for subroutine linkage and for binary arithmetic). The distinctions among computer instructions, pseudo-ops, and macros are not clearly drawn. The syntactic differences between immediate and literal operands are firmly stated more than once, reflecting the fact that their conceptual differences may not have been made clear. Discussions of the computer architecture and of instruction formats are minimal. There are no references, not even to the 370 programmers’ manual.

There is surely a niche for this text, because it is not the only one of its kind on the market. I hope that the above remarks have adequately characterized that niche for the prospective reader.