Intel 9800758-02 manual Commands, Statements

CHAPTER 2

LANGUAGE ELEMENTS

A BASIC-80 program consists of instructions, which tell BASIC-80 what to do, and data, which gives BASIC-80 the inform.ation necessary to do it. This chapter describes the different types of instructions and data, and shows how to represent them.

Instructions

BASIC-80 performs work by interpreting user-provided instructions. These instruc- tions are divided into three categories: commands, statements, and functions. These instruction types are described in the following topics; the individual instructions are described in detail in Chapters 6 and 7.

Commands

Commands are executed as soon as you enter them; they alter or direct entire pro- grams or files. Most commands can be used in program statements, but many of them halt program execution and force variables to zero or null.

Table 2-1 lists the BASIC-80 commands.

Statements

Statements are executed when they are encountered during program execution. They make up most of the instructions of a program. Most statements can be entered as commands.

Table 2-2 lists the BASIC-80 statements.

Table 2-1. BASIC-SO Commands

Command	Description	Example
ATTRIB	Changes the attributes of a file.	ATTRIB "~F1 :STAT", "W1"
AUTO	Automatically numbers program	AUTO 25,500
	statements.
CLEAR	Sets aside memory for strings.	CLEAR 2000
CONT	Continues execution after BREAK.	CONT
DELETE	Deletes a line or lines from a	DELETE 700~875
	program.
DIR	Displays a list of all non-invisible	DIR1
	files on a disk.
EDIT	Specifies a program statement to	EDIT 170
	be changed.
EXIT	Retu rns to operating system .	EXIT
KILL	Deletes a file from disk.	KILL ":F1 :STAT"
LIST	Displays a line or lines of a	LIST 300-400
	program.
LOAD	Retrieves a file from disk.	LOAD ":F1 :DATES"