System information

Memory and I/O Map
VSBC-6 Reference Manual Reference – 53
I/O M
AP
The following table lists the common I/O devices in the VSBC-6 I/O map. User I/O devices
should be added in the 100h – 3FFh range, using care to avoid the devices already in the map as
shown below.
Table 30: On-Board I/O Devices
I/O Device
Standard
I/O Addresses
Alternate *
I/O Addresses
Auxillary Counter/Timer Channels 44h – 47h
Special Control Register 0
E
0h 1
E
0h
Watchdog Hold-Off Register/Revision Register 0
E
1h 1
E
1h
Digital Control / Analog Status Register 0
E
2h 1
E
2h
Map and Paging Control Register 0
E
3h 1
E
3h
Analog Control / ADC Low Register 0
E
4h 1
E
4h
ADC High Data Register 0
E
5h 1
E
5h
Digital I/O Low Data Register 0
E
6h 1
E
6h
Digital I/O High Data Register 0
E
7h 1
E
7h
Primary Hard Drive Controller 1
F
0h – 1
F
7h
Secondary Hard Drive Controller 170h – 177h
Ethernet
Note: Address range 180h – 18
F
h is used to
"park" the Ethernet interface chip when the
Ethernet port is disabled in CMOS Setup.
340h – 34F
h 180h – 18
F
h
280h – 28
F
h
300h – 30
F
h
320h – 32
F
h
360h – 36
F
h
380h – 38
F
h
3
A
0h – 3
Af
h
COM2 Serial Port 2
F
8h – 2
FF
h
COM4 Serial Port 2
E
8h – 2
EF
h
LPT1 Parallel Port 378h – 37
F
h
SVGA Video 3
B
0h – 3
DF
h
COM3 Serial Port 3
E
8h – 3
EF
h
Floppy Disk Controller 3
F
0h – 3
F
7h
COM1 Serial Port 3
F
8h – 3
FF
h
* User selectable via CMOS Setup.
Note Except for the Ethernet interface, the I/O ports occupied by on-board devices are
freed up when the device is disabled in CMOS Setup.