Address Range (Hex) Size Description
------------------------------------------------------------------------
00000000-0007FFFF 512 KB Conventional
00080000-0009FBFF 127 KB Extended conventional
0009FC00-0009FFFF 1 KB Extended BIOS Data
000A0000-000BFFFF 128 KB S3 Trio64V+
000C0000-000C7FFF 32 KB S3 Trio64V+ ROM BIOS (shadowed)
000D8000-000D7FFF 96 KB ISA/PCI space, avail. to ISA adapter ROMs
000E0000-000FFFFF 128 KB System ROM BIOS (ISA bus shadowed)
E000:-E800:0 used for Advanced Power Mgmt. (APM)
00100000-00FFFFFF 15 MB ISA/PCI space
01000000-07FFFFFF 111 MB PCI space
08000000-72FFFFFF 1712 MB PCI space
07300000-737FFFFF 8 MB S3 Trio64V+ linear frame buffer
73800000-FFFDFFFF 2247.9 MB PCI space
FFFE0000-FFFFFFFF 128 KB System ROM BIOS (ISA bus)
Input/Output Address Map Type 6877-6887
The following list show the system board I/O address maps. Any addresses that are not shown are reserved.
I/O Address Map
Address (Hex) Device
------------------------------------------------------------------------
0000-000F DMA 1
0020-003F Interrupt controller 1
0040-0043 Timer 1
0044-0047 Available I/O for ISA/PCI bus
0048-0049 Rapid Resume Advanced Power Mgmt. registers
004A-004B, bits 7,6 CPU speed registers
004C-005F Available I/O for ISA/PCI bus
0060 Keyboard controller data byte
0061 System Port B
0062-0063 Available I/O for ISA/PCI bus
0064 Keyboard controller, command and status byte
0065-006F Available I/O for ISA/PCI bus
0070, bit 7 Enable/disable NMI
0070, bits 6,0 Real time clock address
0071 Real time clock data
0072-007F Available I/O for ISA/PCI bus
0077 DCC setup/presence detect
0078 GPIO CPU speed detect
0079 National 87306 GPIO, A17 for flash
007A National 87306 GPIO
007C-007F L2 Cache ID, tamper EEPROM, SMI/PCI IRQ enable
0080 POST Ckecpoint register
0080-008F DMA page register
0090-0091 Available I/O for ISA/PCI bus
0092 System Port A (not supported)
0093 Available I/O for ISA/PCI bus
0094 Reserved
0095-009F Available I/O for ISA/PCI bus
00A0-00BF Interrupt controller 2
00C0-00DE DMA 2
00DF-00ED Available I/O for ISA/PCI bus
00EE Reserved
00EF Reserved
00F0 Coprocessor busy-Clear
00F1 Coprocessor reset
00F2-00F3 Available I/O for ISA/PCI bus
00F4 Slow CPU
00F5 Fast CPU
00F6-00FF Available I/O for ISA/PCI bus
0100-0105 Reserved riser
0106-016F Available I/O for ISA/PCI bus
0130-013F Default for data collaboration card (DCC)
0170-0177 IDE channel 1
01B0-01BF Alternate for data collaboration card (DCC)
01F0-01F7 IDE channel 0
01F8-021F Available I/O for ISA/PCI bus
0220-0227 National 87306, serial port 3 or 4
0228-0277 Available I/O for ISA/PCI bus
0230-023F Alternate for data collaboration card (DCC)
0278-027F National 87306, parallel port 3
0280-02E7 Available I/O for ISA/PCI bus
02B0-02BF Alternate for data collaboration card (DCC)
02E0-02EF National 87306, serial port 3 or 4
02F0-02F7 Available I/O for ISA/PCI bus
02F0-02FF National 87306, serial port 2 (system board)
0300-0337 Available I/O for ISA/PCI bus
0338-033F National 87306, serial port 3 or 4
0340-0375 Available I/O for ISA/PCI bus
0376-0377 IDE channel 1
0377, bit 7 IDE, diskette change
0378-037F National 87306, parallel port 2
0380-03B3 Available I/O for ISA/PCI bus
03B4-03BB S3 Trio64V+
03BC-03BE National 87306, parallel port 1 (system board)
03BF-03DF S3 Trio64V+
03E0-03E7 Available I/O for ISA/PCI bus
03E8-03EF National 87306, serial port 3 or 4
03F0-03F5 National 87306, diskette channel 0
03F6 IDE channel 0
03F7, bit 7 IDE, diskette change
03F7, bits 6,0 IDE channel 0
03F8-03FF National 87306, serial port 1 (system board)
0400-0537 Available I/O for ISA/PCI bus
0CF8-0CFB PCI configuration address register
0CFC-0CFF PCI configuration data register
0D00-0FE7 Available I/O for ISA/PCI bus
42E8 S3 Trio64V+
42E9-4AE7 Available I/O for ISA/PCI bus
4AE8 S3 Trio64V+
4AE9-82E7 Available I/O for ISA/PCI bus
82E8 S3 Trio64V+
82E9-86E7 Available I/O for ISA/PCI bus
86E8 S3 Trio64V+
86E9-8AE7 Available I/O for ISA/PCI bus
8AE8 S3 Trio64V+
8AE9-8EE7 Available I/O for ISA/PCI bus
8EE8 S3 Trio64V+
8EE9-92E7 Available I/O for ISA/PCI bus
92E8 S3 Trio64V+
92E9-96E7 Available I/O for ISA/PCI bus
96E8 S3 Trio64V+
96E9-9AE7 Available I/O for ISA/PCI bus
9AE8 S3 Trio64V+
9AE9-9AE7 Available I/O for ISA/PCI bus
9EE8 S3 Trio64V+
9EE9-A2E7 Available I/O for ISA/PCI bus
A2E8 S3 Trio64V+
A2E9-A6E7 Available I/O for ISA/PCI bus
A6E8 S3 Trio64V+
A6E9-AAE7 Available I/O for ISA/PCI bus
AAE8 S3 Trio64V+
AAE9-B2E7 Available I/O for ISA/PCI bus
B2E8 S3 Trio64V+
B2E9-B6E7 Available I/O for ISA/PCI bus
B6E8 S3 Trio64V+
B6E9-BAE7 Available I/O for ISA/PCI bus
BAE8 S3 Trio64V+
BAE9-BEE7 Available I/O for ISA/PCI bus
BEE8 S3 Trio64V+
BEE9-E2E7 Available I/O for ISA/PCI bus
E2E8 S3 Trio64V+
E2E9 Available I/O for ISA/PCI bus
E2EA S3 Trio64V+
E2EB-FFFF Available I/O for ISA/PCI bus
DMA I/O Address Map Type 6877-6887
DMA I/O Addresses for Memory Addresses, Word Counts and Command/Staus Registers
Address Description Bits Byte
(Hex) Pointer
------------------------------------------------------------------------
0000 Channel 0 Memory Address register 00-15 yes
0001 Channel 0 Transfer Count register 00-15 yes
0002 Channel 1 Memory Address register 00-15 yes
0003 Channel 1 Transfer Count register 00-15 yes
0004 Channel 2 Memory Address register 00-15 yes
0005 Channel 2 Transfer Count register 00-15 yes
0006 Channel 3 Memory Address register 00-15 yes
0007 Channel 3 Transfer Count register 00-15 yes
0008 Channels 0-3 Read Status/Write Command register 00-07
0009 Channels 0-3 Write Request register 00-02
000A Channels 0-3 Write Single Mask register bits 00-02
000B Channels 0-3 Mode register (write) 00-07
000C Channels 0-3 Clear byte pointer (write) N/A
000D Channels 0-3 Master clear (write)/temp (read) 00-07
000E Channels 0-3 Clear Mask register (write) 00-03
000F Channels 0-3 Write All Mask register bits 00-03
0081 Channel 2 Page Table Address register * 00-07
0082 Channel 3 Page Table Address register * 00-07
0083 Channel 1 Page Table Address register * 00-07
0087 Channel 0 Page Table Address register * 00-07
0089 Channel 6 Page Table Address register * 00-07
008A Channel 7 Page Table Address register * 00-07
008B Channel 5 Page Table Address register * 00-07
008F Channel 4 Page Table Address Refresh/reg. 00-07
00C0 Channel 4 Memory Address register 00-15 yes
00C2 Channel 4 Transfer Count register 00-15 yes
00C4 Channel 5 Memory Address register 00-15 yes
00C6 Channel 5 Transfer Count register 00-15 yes
00C8 Channel 6 Memory Address register 00-15 yes
00CA Channel 6 Transfer Count register 00-15 yes
00CC Channel 7 Memory Address register 00-15 yes
00CE Channel 7 Transfer Count register 00-15 yes
00D0 Channels 4-7 Read Status/Write Command register 00-07
00D2 Channels 4-7 Write Request register 00-02
00D4 Channels 4-7 Write Single Mask register bit 00-02
00D6 Channels 4-7 Mode register (write) 00-07
00D8 Channels 4-7 Clear byte pointer (write) N/A
00DA Channels 4-7 Master clear (write)/temp (read) 00-07
00DC Channels 4-7 Clear Mask register (write) 00-03
00DE Channels 4-7 Write All Mask register bits 00-03
00DF Channels 5-7 8-or-16 bit mode select 00-07
* Upper byte of Memory Address register
Please see the LEGAL - Trademark notice.
Feel free - send a 
for any BUG on this page found - Thank you.