6530 Programmer's Guide

Conversational Mode Operation
2-16
6530 Programmer’s Guide
Underline background color. Specifies one of 8 colors used to
display the background for the underscore attribute. (The default
underline background color is blue.)
Underline mapping. Specifies on or off. When on, space (20H)
characters with the underscore attribute are mapped to underline
(5FH) characters. (The default for underline mapping is off.)
PC6530 maps characters with the underscore or invisible attributes
before mapping other video attributes. All characters with the invisible
attribute are mapped to space (20H) characters. Thus, the foreground
color for characters with the invisible attribute is not displayed.
Your application program cannot set any of the above parameters (with
the exception of normal intensity). However, using the Esc-q sequence,
you can redefine (set) the color map table used when color mapping is
selected. (See “Set/Reset Color Map Table (Esc - q)” on page 2-19.)
Color Enhancement Query (Esc ?)
The host application recognizes that a 6530 device can support field-
selectable color through the reply to a Read Configuration escape
sequence (Esc ?) when that reply contains an ASCII lower case letter e
(65h), followed by a byte that specifies the current color support
available. In conversational mode, this is a read-only operation. The
following illustration shows the bit field definition.
PC6530 uses all of the 16 foreground colors and 8 background colors
defined by the BIOS interface.
Bit 6543210
Level of color support
(valid range 0 - 31)
0 = no color support
1 = non-configurable color
support
2 = configurable 16 of 64 colors
(PC EGA)
3 = configurable 16 of 254 colors
(PC VGA)
4 to 31= reserved for future
support
1
EOA support (always 0 for 6530)