Precise Scientific Computation with a Microprocessor

When a high-level programming language is used for scientific computation, usually one must use standard floating point and choose the precision-single, double, or higher-before one's program executes. This paper describes a modified Basic that accommodates the advanced computation techniques of dynamic adjustable precision and interval arithmetic. This language-Precision Basic or Pbasic-allows a user to routinely obtain his n decimal place answers accurate to the last decimal place. An interpreter for this modified Basic was recently completed that runs on a Z-80 microprocessor. Some features of the interpreter are described.