Article ID: 35148
Article Last Modified on 11/21/2006
APPLIES TO
- Microsoft QuickBasic 4.0, when used with:
- Microsoft MS-DOS 6.22 Standard Edition
- Microsoft QuickBASIC 4.0b, when used with:
- Microsoft MS-DOS 6.22 Standard Edition
- Microsoft QuickBasic 4.5 for MS-DOS, when used with:
- Microsoft MS-DOS 6.22 Standard Edition
- Microsoft BASIC Professional Development System 7.0
- Microsoft GW-BASIC 3.2
- Microsoft GW-BASIC 3.22
- Microsoft GW-BASIC 3.23
- Microsoft BASIC Compiler 6.0
- Microsoft BASIC Compiler 6.0b
This article was previously published under Q35148
SUMMARY
On the Hercules Graphics Adapter (HGA) or the IBM Monochrome Display Adapter (MDA), the foreground and background arguments of the COLOR statement support underlined, reverse-video (highlighted), blinking, or high-intensity characters. Reverse/underline and intense/reverse combinations are not supported by HGA or MDA.
MORE INFORMATION
The following 11 combinations of COLOR statement foreground and background values are available on monochrome, SCREEN 0 (text) displays:
FORMAT COLOR Statement ATTRIBUTE
White on black (normal) COLOR 7,0 7
Black on black (no display) COLOR 0,0 0
Black on white (reverse) COLOR 0,7 112
Underline COLOR 1,0 1
Intense COLOR 10,0 10
Blinking COLOR 18,0 130
Reverse blinking COLOR 16,7 240
Intense underline COLOR 9,0 9
Intense blinking COLOR 26,0 138
Underline blinking COLOR 17,0 129
Intense blinking underline COLOR 25,0 137
This information applies to the following products:
- Microsoft QuickBasic Compiler Versions 4.00, 4.00b, 4.50
- Microsoft Basic Compiler Versions 6.00 and 6.00b for MS-DOS and MS OS/2
- Microsoft Basic PDS Version 7.00 for MS-DOS and MS OS/2
- Microsoft GW-Basic Interpreter Versions 3.20, 3.22, and later
In SCREEN 0 with a color card (CGA, EGA, or VGA), the COLOR statement is used to change the foreground and background colors that are displayed. The COLOR statement also lets you select intense or blinking options for the foreground color. Underlining is not supported on color monitors.
In text mode (SCREEN 0), two consecutive bytes are used to store each character in screen memory. One byte contains the ASCII value of a character, and the following byte contains ATTRIBUTE information for that character. Attributes can be calculated with the following formula:
ATTRIBUTE = 128*(FOREGROUND\16)+BACKGROUND*16+(FOREGROUND MOD 16)
[Note: The backslash character (\) is the integer division operator.]
See Pages 79-81 of "The Peter Norton Programmer's Guide to the IBM PC" (published by Microsoft Press, 1985) for more information about attributes.
The following book from Microsoft Press describes video details more completely:
"Programmer's Guide to PC & PS/2 Video Systems," by Richard Wilton (1987). Chapter 3 describes the alphanumeric video modes.
The following is a code example:
'This program will display all of the character formats resulting from
'each of the 32 foreground colors available for any of the 8
'recognized background colors with a monochrome card in SCREEN 0 (text
'mode).
DEFINT A-Z
5 CLS
LOCATE 20, 15
COLOR 7, 0
liner = 0
INPUT "background="; back
FOR fore = 0 TO 31
IF liner = 16 THEN
liner = 0
END IF
liner = liner + 1
LOCATE liner, 1 + (20 * (fore \ 16))
PRINT fore; back;
COLOR fore, back
PRINT "A"
COLOR 7, 0
NEXT fore
WHILE INKEY$ = "": WEND
GOTO 5
Additional query words: QuickBas BasicCom
Keywords: KB35148
