
THE INTERRUPT STRUCTURE OF 8086 8-17
Solution
Look at Tables 8.4, 8.5 and 8.6.
i) For black background, the RGB values are 000, and since blinking is not mentioned,
it is ‘normal’. Hence, the nibble corresponding to the background is 0000.This is to
be the bits D
7
to D
4
of the attribute byte.
The lower four bits of the attribute is 0111.
Thus, the attribute bye is 0000 0111, i.e., 07.
ii) No blinking. Hence, D
7
= 0.
White background needs 111.
Red foreground (text) needs 0100.
Thus, the attribute byte is 0111 0100, i.e., 74H.
iii) Blinking and cyan background needs 1011.
Brown foreground (text) needs 0110.
Thus, the attribute byte is 1011 0110, ...