Now programmers can refresh their memory quickly and easily with this essential desk reference. For the first time in one volume, this easy-to-use guide collects all the information a programmer needs on IBM mainframe software products, programmers' utilities, and computer languages. Organized for fast information retrieval, this invaluable tool includes all the most commonly used codes and messages for mainframe software, along with key words and their usages for all the languages applicable to the most popular mainframe environments-MVS, VM, and VSE. For each of the programs or languages, all commands are briefly discussed with general forms of usage and lots of examples.