Microsoft KB Archive/22036

= SCREEN 7,8,9 "Illegal Function Call" Using Foreground COLOR 0 =

Article ID: 22036

Article Last Modified on 11/21/2006



This article was previously published under Q22036



SUMMARY
Executing the COLOR statement with a zero (0) as the foreground color gives "Illegal Function Call" on the EGA SCREEN modes 7, 8, and 9. For example: 10 SCREEN 9 20 COLOR 0,0  ' Gives "Illegal function call" This is because zero (0) is not within the allowed range of attributes with the EGA. The range of attributes is 1 to 3 for an EGA with 64K, and 1 to 15 for an EGA with more than 64K of memory.

You can work around this behavior by using the PALETTE statement to reassign the color of zero to another attribute number. This can be accomplished by doing the following: DIM Pal%(16) SCREEN 7 Pal%(0) = 15 Pal%(15) = 0 PALETTE USING Pal%(0) COLOR 15,1 CLS This information applies to QuickBasic versions 2.00, 2.01, 3.00, 4.00, 4.00b, and 4.50; to Microsoft Basic Compiler versions 6.00 and 6.00b for MS-DOS, and to Microsoft Basic Professional Development System (PDS) versions 7.00 and 7.10 for MS-DOS.



MORE INFORMATION
Another way to simulate a foreground color of zero (0) in screen mode 9 or 12 is shown in a separate article in this Knowledge Base. To find this article, query on the following words:

foreground and background and GET and PUT and 16 and simultaneously

(The graphics GET and PUT technique and sample program shown in this separate article could be modified for QuickBasic 2.0x and 3.00.)

Additional query words: QuickBas BasicCom

Keywords: KB22036

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