Zenith Z-100 Series, Reference Manual

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Page 7.13
Video Graphics Programming
For a given pixel bit pair composed of bits CO and Cl, the following logic, as
shown in Tables 7.4 and 7.5, determines which color is selected from one of
four colors: the current background color or one of the three colors from the
current palette.
Table 7.4. Color Select Logic
Cl CO CO LO R S ELECT CODE
Pixel becomes the current background color.
Pixel becomes color ¹I of current palette.
Pixel becomes color ¹2 of current palette.
Pixel becomes color ¹3 of current palette.
Table 7.5. Palette Structure
C OLOR ¹ SET I
I
Cyan
Magenta
3 White
SET 2
Green
Red
Brown
The possible background colors are the same basic eight colors used in low resolu-
tion graphics, plus the lighter shades of these colors. This results when intensified,
for a total of sixteen colors induding black and white as shown in Table 7.3.
In order to obtain the lighter (intensified) shades, the monitor being used must
be capable of recognizing the "I" bit