INT 10H 1003H: Select Foreground Blink or Bold Background
Compatibility: EGA VGA
Expects: AX 1003H
BL 00H = enable bold backgrounds (16 background colors)
01H = enable blinking foreground (8 background colors)
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Returns: (none)
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Info: This enables or disables blinking foreground colors in EGA/VGA
text modes. By default, the BIOS enables blinking foregrounds
(characters blink when bit 7 of the Video Attribute is set).
When foreground blink is disabled (BL=00H), all 16 colors are
available for use as background colors.
Notes: This fn is not available on CGAs▲ and MDAs▲. To use this
attractive and often-seen effect, you must program the CGA Mode
Select Register, manually clearing bit 5. See CGA I/O Ports.
For instance:
mov ax,40H
mov es,ax
mov dx,es:[063H] ;get port address of the card
add dx,4
mov al,es:[065H] ;get current value of Mode Select Register
and al,0dfH ;mask value by 1101 1111 (to clear bit 5)
out dx,al ;disable blink (set for bold background)
mov es:[065H],al ;save the new setting
See Also: INT 10H 10H: EGA/VGA Palette Functions
INT 10H: Video Services
EGA/VGA Data Areas
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