Intel 815 Manuel D’Utilisation
Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
R
82
9.1.3. FCR
Feature Control
I/O (and Memory Offset) Address: 3BAh/3DAh
Write; 3CAh Read
Default: 00h
Attributes:
Attributes:
See Address above
The address selection for reads is dependent on CGA or MDA emulation mode as selected via the MSR
register.
register.
7
4
3
2
0
Reserved (0000)
VSYNC
Control
Reserved (000)
Bit Descriptions
7:4
Reserved. Read as 0.
3
VSYNC Control.
0 = Vsync output on the VSYNC pin (default).
1 = Logical 'OR' of VSync and Display Enable output on the VSYNC pin. This capability is provided for
IBM compatibility.
IBM compatibility.
2:0
Reserved. Read as 0.