ACT apricot - Page 87

CRT CONTROL
address, see System RAM description below). The attribute
bits are defined as follows:
015 014 013 012 011
~
I ~Software attribute
L St rikethrough
Underline
'---- Hi ghl i gh t
-----Reverse Video
Software Attribute {DII}. This bit is for use by applications
programs
to mark screen characters for various display
functions, e.g.
mark the beginning of a line, end of a block of
text, etc.
The bit is not used for display generation
functions.
Strikethrough {DI2}. This bit works in conjunction with
one of the non-displayed bits within a font cell. If the
strikethrough bit is set; a horizontal line is superimposed
through the character, at a position determined by bit 14 in
the font cell (see System RAM description).
Underline (DI3). This bit works in conjunction with one of
the non-displayed bits within a font cell. If the underline bit
is set, a horizontal line is drawn the full width of the
character cell, underneath the character at a height
determined by bit 15 in the font cell (see System RAM
description).
Highlight {DI4}. If this bit is set, the character is displayed
in high intensity on the screen. If not set, the character is
displayed
in normal intensity.
Reverse Video {DI5}. If this bit is set, the character,
underline and strikethrough are all displayed in reverse
video, (i.e. black
character on a green background). If not set,
the character is displayed in normal video (green character
on a black background).