Basic Primer; Basic Basics - AMSTRAD CPC464 User Manual

3 BASIC primer

A brief introduction BASIC language to programs written using
the AMSTRAD
Subjects covered in this chapter
* The rules of syntax and descriptions of syntax
* The PRINT commands, streams and display formatting
* ZONES

3.1 BASIC basics

The fundamental relationship of the CPC464' s built-in BASK! to the internal operation of the
computer is introduced in Appendix II. If you have not previously programmed a computer, then
we' ll try and help you along gently - but it may be necessary to make some assumptions that might
cause confusion to the novice. If so, we suggest that you browse through the many books available
that are designed to introduce the fundamentals of programming to the newcomer.
You should be able to work through this chapter following the simple exercises herein without
requiring a complete appreciation of what' s happening – although the more of the rules you learn,
the easier it will all become.
BASIC is the language that comes supplied ' built-in' with your CPC464. It' s right there when you
switch on, and makes it' s presence felt with the prompt word:
Ready
BASIC is the simplest language to learn. It is organised with clearly defined words and ' grammar' ,
and operates completely logically - as long as you understand the rules.
AMSTRAD BASIC is capable of executing the commands given in Chapter 8. Each command is
identified by one or more leading keywords, and may have a number of parameters - some of which
are optional. In general each parameter may be an expression, involving constants, variables and
functions. Combinations of numbers and letters are known as strings, and various forms of numeric
data types are supported including decimal, hexadecimal and binary types.
Files on the cassette are handled sequentially ie one after another - as opposed to randomly, where a
file can be selected directly from the midst of many others without first passing through the
unwanted files.