IBM High Level Assembler (Hlasm)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. HLASM is IBM's high-level assembler product for its z/OS, z/VSE, z/VM and z/TPF operating systems, which run on its z/Architecture mainframe computers. There is also a version that runs under Linux, primarily intended for systems running on a z/Architecture system (this environment is sometimes referred to as z/Linux). Based on IBM's H assembler, it allows assembler programmers to write code that utilizes some features normally associated with high level languages. Some of these features include labelled and dependent USINGs, more complete cross-reference information, and additional macro language capabilities such as the ability to write user-defined functions.