Graphics Primer; Machine-Specific Features; Colour Selection - AMSTRAD CPC464 User Manual

5 Graphics Primer

Finding your way around the colour and graphics of the CPC464
Subjects covered in this chapter:
* Screen Modes and pixels
* The colours
* INK, PAPER and PEN
* Drawing Lines
* WINDOWS

5.1 Machine-specific features

The description and applications of AMSTRAD BASIC have so far largely been based on an industry-
standard specification. Most of the purely arithmetical operations will run with only slight
adjustments from one ' dialect' of BASIC to another however, the BASIC commands that control the
graphics (and the text cursor locations) are more specifically dedicated to the way in which the
CPC464 hardware controls the screen display and must be carefully understood to get the most from
your micro.
As usual BASIC KEYWORDS are shown displayed in the special computer display style typeface,
further examples and a concise description of the keyword and its use can be found by reference to
the appropriate entry in chapter 8.

5.1.1 Colour Selection

' Black' ie no colour or illumination is considered as a colour for the purposes of all following
descriptions that describe the attributes of the colours and the various commands associated with
them.
The BORDER can be set to a ANY pair of colours regardless of the screen mode, and is not reset
when a MODE command is issued. It may be set to flash, or to a single steady colour.
The number of available INK s that may be displayed simultaneously depends on the screen MODE
selected. Each INK can be set to a pair of colours ie flashing; or a single colour ie steady. The
number of usable inks at any time depends on the screen mode as previously defined. The text
PAPER , text PEN , and graphics PEN can then be set to an available ink.