Waterloo BASIC for VM/CMS and MVS/TSO

Software Description

Waterloo BASIC Compiler

Waterloo BASIC is an incremental compiler implemented for System/370 architecture machines running VM/SP CMS and MVS/TSO. Waterloo BASIC combines the inherent simplicity of the original Dartmouth BASIC with enhancements for structured programming, powerful string-handling capabilities and the interactive nature of incremental compilation. The result is a system which promotes the use of modern program design techniques, making it an ideal tool for introductory courses in computing and for the development of application systems.

Waterloo BASIC Optimizer

The Waterloo BASIC Optimizer is a post-processor for programs compiled using the Waterloo BASIC Compiler. It may be used to increase the performance of production programs. Experimental results indicate that most programs execute at least twice as fast using the Optimizer.

Optimized programs function identically to compiled programs. The same error diagnosis is performed when an optimized program is executed.

The size of an optimized file is smaller than the corresponding size of a compiled program. This reduces disk space requirements as well as program load time.

The Waterloo BASIC Optimizer is useful in environments where programs are executed many times without change or where programs perform a large amount of computation.

Features of the Waterloo BASIC Compiler

Comprehensive diagnostics, interactive debugging and simple operational characteristics promote student self-help and ease of use.

• Program statements are compiled one at a time as they are entered at the terminal. Error diagnostics are displayed as soon as a problem is evident.
• Programs may be interrupted, changed, and allowed to continue execution. Debugging is accomplished using BASIC language statements that are compiled and executed immediately.
• Editor commands allow lines to be added, deleted or changed in a program. Program source statements may be saved, or the program environment may be stored and restored eliminating recompilation.
• Character-string management at run-time is dynamic, allowing strings to vary from 0 to 65535 bytes. An extensive set of built-in string-processing functions is included.
• Variable names may be as long as desired, allowing names which are representative of the values they contain.
• A set of control structures has been added to the language to facilitate structured programming. The WHILE and UNTIL statements may be used to control the iteration of loops. The IF-ELSE-ENDIF construct enables groups of statements to be selected for execution.
• Waterloo BASIC supports standard CMS and MVS file types. This permits data to be manipulated by programs written in other languages, or by common system utilities. Indexed files allowing record access via keys are also supported and are implemented based upon standard file formats. The BASIC file system does not make use of VSAM for file access.
• Two statements used to control the sorting of files are included.
• Extensive formatting capabilities permit data to be input or output in a wide variety of formats.
• Structured program control encourages programming in a logical manner rather than the traditional "Spaghetti code". More emphasis can be placed on algorithms and program development.
• Under CMS, an intrinsic function is provided which allows CMS commands, CP commands or EXEC files to be invoked from a BASIC program.
• Descriptions of BASIC statements and commands can be obtained using the BASIC HELP command.
• Parameters can be passed to both procedure and function program modules.
• Terminal input and output recording is ideal for beginning programming assignments since the student does not need specific file expertise to create an output file suitable for marking.
• Included is a full complement of matrix functions such as matrix multiplication and matrix inverse which are useful for many engineering and mathematical problems.
• The Waterloo BASIC Compiler can be implemented as a CMS shared segment to provide shared code among BASIC users, reduced paging and lower virtual memory requirements.
• The Waterloo BASIC Compiler is currently available for the following systems:
  • IBM VM/SP CMS
  • IBM MVS/TSO
• The Waterloo BASIC Optimizer is currently available for the following system:
  • IBM VM/SP CMS

Documentation

The Waterloo BASIC Primer and Reference Manual (Graham, Welch and McPhee; ISBN 0-919884-22-9; WATCOM Publications, 1983) is the primary reference for Waterloo BASIC. The text consists of two major components: a primer which provides a basic introduction to the language, and a reference manual which comprehensively defines the syntax and semantics of the Waterloo BASIC language.