Radio Shack TRS-80 PC-3 User Manual

The PC-3 implements logical operators as "bitwise" logical functions on 16-bit quantities. (See note on relational expressions and
True and False.) In normal operations this
is not significant because the simple 1 and 0 (True and False), which result from a
relational expression,
use only a single bit. If you apply a logical operator to a value other than 0 or 1, it works on each bit in-
dependently.
For example, if A is 17 and B is 22, (A or B) is 23:
17 in binary
notation is 10001
22 in binary notation is 10110
17 OR 22
is 10111 (1 if 1 in either number, otherwise 0)
10111
is 23 in decimal.
If you are a proficient programmer, there are certain applications where this type of operation can be very useful. Beginning pro-
grammers should stick
to clear, simple True or False relational expressions.
Parentheses and Operator Precedence
When evaluation complex expressions the PC-3 follows a predefined set of priorities which determine the sequence in which opera-
tors
are evaluated. This can be quite significant.
5 + 2 *3 could be:
7
21
or
6
11
The exact rules of "operator precedence" are given in Appendix D.
To avoid having to remember all these rules and to make your program clearer, always use parentheses to determine the sequence
of evaluation. The above example is clarified by writing either:
55

Radio Shack TRS-80 PC-3 Specifications

General

Type	Programmable Calculator
Model	TRS-80 PC-3
Category	Calculator
RAM	1.9 KB
Display	24-character LCD
Power Source	2x CR2032 batteries

Summary

Limited Warranty

Radio Shack Limited Warranties

Details warranty period, conditions, and remedies for equipment defects.

Limitation of Liability

Outlines restrictions on Radio Shack's liability for damages.

Service Policy

Chapter 2: Introduction to the PC-3

Reset and Battery Management

Procedures for resetting the PC-3 and replacing batteries.

Chapter 3: Using the PC-3 as a Calculator

Simple Calculations

Performing basic arithmetic and understanding input/output.

Handling Errors

Addressing error messages and their solutions.

Chapter 4: Concepts and Terms of BASIC

Variables and Expressions

Understanding constants, variables, and their usage.

Chapter 5: Programming the PC-3

BASIC Statements and Commands

Introduction to BASIC syntax, verbs, and commands.

Chapter 7: Using the PC-3 Printer/Cassette Interface

Cassette Recorder Operations

Saving and loading programs and data on tape.

Chapter 8: BASIC Reference

Commands Reference

Instructions for controlling the computer's environment.

Verbs Reference

Action words used within BASIC programs.

Functions Reference

Mathematical and string manipulation operations.

Chapter 10: Troubleshooting

Machine Operation Issues

Solutions for common problems with device functionality.

BASIC Debugging Tips

Strategies for finding and correcting program errors.

Appendix A: Error Messages

Appendix F: Specifications