VDU 19 (changes)
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Programmer's Reference Manuals
» VDU Codes
» VDU 19
VDU 19 (&13)
Use
Selects the actual colour that is to be displayed for each logical colour.
Syntax
VDU 19,logical colour,mode,red,green,blue
Parameters
| logical colour | Colour to set |
| mode | how to set the colour |
| red, green, blue | physical colour information |
Use
VDU 19 defines the colour palette relationship. It causes a specified logical colour for either the screen, border or pointer to be represented by a given physical colour.
The action depends on the value of ‘mode’ as follows:
| mode = 0 – 15 | logical colour = physical colour specified by mode parameter. red, green and blue are ignored, and should be zero |
| mode = 16 | both flash palettes for logical colour = red units red, green units green, blue units blue |
| mode = 17 | first flash palette for logical colour = red units red, green units green, blue units blue |
| mode = 18 | second flash palette for logical colour = red units red, green units green, blue units blue |
| mode = 24 | border colour = red units red, green units green, blue units blue; logical colour is not used, and should be zero |
| mode = 25 | logical colour (1 – 3) of pointer = red units red, green units green, blue units blue |
If you add 128 to the ‘mode’ value, you also set the ‘supremacy’ bit of the appropriate palette entry. This is used when the computers’ video is mixed with an external video source, to provide a superimposed image.
Notes
Use of semi-colon punctuation sends in number as two-byte pair: lo followed by hi.BASIC sends number as two-byte pair: lo followed by hi.
See also
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