SCREEN 1 COLOR Yellow Is Brown (Muddy) on EGA Versus CGA Card (21969)

SUMMARY

The following program, which uses the COLOR statement on SCREEN 1, may give different colors on a machine with an EGA card compared to the colors on a machine equipped with a CGA card:

10 SCREEN 1
20 COLOR 8,0
30 LINE (30,100)-(40,150),3,bf
40 LINE (10,40)-(60,100),2,bf
50 LINE (100,100)-(130,130),1,bf

The background color selected is dark gray (8). Palette 0 is selected, and includes red, green, and yellow on a CGA. Under QuickBasic on an EGA card, the colors may appear "muddy" compared to running on a CGA card: the red and green are less intense than shown on a CGA card and the yellow is brown.

This is not a problem with QuickBasic, but is a difference between CGA and EGA cards. The EGA allows only nonintensified colors. The same colors occur on an EGA card in the Microsoft GW-Basic Version 3.20, 3.22, or 3.23 Interpreter on an EGA card.

MORE INFORMATION

Note that in SCREEN 1 on an EGA or VGA, the PALETTE statement can change the color used by output from the PRINT statement, for example

PALETTE 3,n

where n can be a color from 0 to 15. On an EGA card, PALETTE 3,6 (where 6 is brown) is the default. PALETTE 3,14 will make PRINT output appear in yellow.

The PALETTE statement is not supported on CGA cards. On a CGA card, the color of text output with the PRINT statement can only be changed to one of two possible colors by changing the palette argument of the COLOR statement. For example

COLOR b,p

where b is the background color, and p (the palette) can be 0 or 1. If the p argument is 0, PRINT output displays in color number 6 (brown on an EGA, yellow on some CGA cards). If the p argument is 1, PRINT output displays in color number 7 (white). See the COLOR statement in the Basic language reference documentation for more information.

Graphics statements such as LINE and CIRCLE can use color (attribute) arguments 0, 1, 2, or 3 to allow simultaneous display of four colors at once (including the background) in SCREEN 1 on CGA, EGA, or VGA.