AMSTRAD CPC464 User Manual page 194

You will find that your CPC464 compares very favourably with any similarly priced machine in all
these respects.
2. The BASIC interpreter
Virtually every home computer includes with it a BASIC interpreter that allows the user to start
creating programs to use the hardware features. The built in programming language (BASIC) that
comes supplied with your machine is itself a program - an immensely complicated and intricate
program that has been evolved over a million man-years of experience since BASIC was ' invented' in
the USA. The ' Beginners All-purpose Symbolic Instruction Code' is easily the most widely used
computer language in the world, and like any language, it comes in a variety of local ' dialects' .
The version in the CPC464 is one of the most widely compatible dialects of BASIC, and will run
many of the common BASIC programmes written for operation under the CP/M disk operating
system. It is a very fast implementation of BASIC – in other words it performs its calculations
quickly - and whilst you may not be too concerned that one computer may take 0.05 of a second to
multiply 3 by 5, and display the answer whereas another may take 0.075 second to do the same -
where a program that draws graphics patterns on the screen may call for many thousands of simple
repetitive calculations, the difference between 0.05 second and 0.075 of a second adds up to a
considerable difference in performance.
You will frequently hear the term ' machine code' being used. Machine code is the raw form of
instruction code that can be passed to the processor. It takes less time to work out what it' s been
asked to, and gets on with producing the result some 5 to 15 times faster than an equivalent
operation being passed along through the BASIC interpreter. But it can take 5 to 50 times longer to
write an equivalent program in machine code when compared to performing the same overall task
using BASIC.
The BASIC in your Amstrad computer is amongst the fastest and most fully featured to be found in
any home computer system, and incorporates many features that help the experienced BASIC
programmer overcome some of the inherent sluggishness of a ' high level language' interpreter to
perform surprisingly dynamic visual and musical effects.
3. Expandability
Most computers pay attention to the need to ' add on' additional items of hardware: printers,
joysticks, disk drives. Paradoxically, some of the most successful home computers require the
addition of add-on units known as ' expansion interfaces' before even a simple printer or joystick
controller can be installed.