VT8601 Via, VT8601 Datasheet - Page 80

• Manufacturer Part Number: VT8601
• Description: Slot-1 / Socket-370 PCI North Bridge
• Manufacturer: Via

VGA Extended Registers
VGA Extended Registers – Non-Indexed I/O Ports
Port 3D8 – Alternate Destination Segment Addr ........... RW
Read / write of this register is enabled by GRF[2].
This register becomes active when GR6[3-2] are not 00.
Port 3D9 – Alternate Source Segment Address .............. RW
Read / write of this register is enabled by GRF[2].
This register becomes active when GR6[3-2] are not 00.
Revision 1.3 September 8, 1999
6-0
6-0
7
7
7HFKQRORJLHV ,QF
Reserved
Alternative Destination Segment Address . def = 00
Reserved
Alternative Source Segment Address ......... def = 00
:H &
:H &R R QQHFW
QQHFW
........................................ always reads 0
........................................ always reads 0
-74
Port 3xB – Alternate Clock Select ................................... RW
3xB notation indicates that this register is accessible at either
3BB or 3DB depending on the setting of the color / mono bit.
7-5
4-2
1-0
New Mode Control Register Bits 3-1 ..........def = 00
These bits have the same function as SRD[3-1]
Reserved
Video Clock Select ........................................def = 00
........................................always reads 0
VT8601 Apollo ProMedia
VGA Extended Registers