www.riscos.com Technical Support: BBC BASIC Reference Manual

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About the BBC BASIC Reference Manual

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This manual provides a complete description of BBC BASIC, one of the most popular and widely-used programming languages.

Intended readership

You should read this manual if you are

• a computer user who has never used BBC BASIC before, who wants an introduction to a new computer language;
• an experienced programmer in other computer languages, who wants an insight into BBC BASIC's features without having to resort to a lengthy tutorial-type manual;
• an experienced BBC BASIC programmer, who needs specific information about the structure of BBC BASIC, and the use of its commands.

Structure of the manual

The manual is divided into the following parts:

Part 1: Overview -- includes this chapter, and the chapter entitled About BBC BASIC, which gives an introduction to BASIC VI. It compares BASIC VI with BASIC V, and describes the benefits and effects of using both versions.

Part 2: Programming techniques -- explains how to program in BBC BASIC, and introduces many of the commands (or keywords) provided by the language. The last chapter in this section describes the BASIC screen editor.

Part 3: Keywords -- contains a complete list of BBC BASIC keywords, in alphabetical order. It defines the syntax of all the keywords, and gives you examples of how to use them.

Part 4: Reference -- contains the appendices, which have useful reference material, such as numeric representation, error messages, keyword abbreviations and VDU commands. The chapter entitled Basic History gives a brief history of BBC BASIC.

Conventions used in this manual

The following conventions are applied throughout this manual:

• Specific keys to press are denoted as Ctrl, Delete and so on.
• Instructions which require you to press a combination of keys are shown thus: Shift-Break means hold down the Shift key and press and release the Break key.
• Text you type on the keyboard and text that is displayed on the screen appears as follows:

  PRINT "Hello"

• Classes of item are shown in italics: For example, in the descriptions of BASIC keywords, you might see something like:

  LET var = expression

  where var and expression are items you need to supply, for example:

  LET a$="hello"

• Items within square brackets [] are optional. For example,

  GCOL [expression2,] expression1

  means that you must supply at least one expression. If you supply two, you must separate them with a comma.

• All interactive commands are entered by pressing the Return key. However, this is not actually shown in the examples or syntax of commands.
• Extra spaces are inserted into program listings to aid clarity, but need not be typed in.
• Program listings are indented to illustrate the structure of the programs.

If at any time you wish to interrupt a program the computer is executing you can do so safely by pressing Esc.

Feel free to experiment. Try modifying the programs listed in this manual and writing new ones of your own.