5-8
C
HAPTER
5: C
ONFIGURING
THE
NIC M
ANUALLY
3Com mode increases the number of available IRQ
channels from 4 to 8 and the number of I/O base
addresses from 2 to 31. You can install up to six 3C319
NICs per PC. 3Com drivers are supplied on the
TokenDisk
diskettes to support these 3Com mode enhancements.
The default is 3Com mode.
IBM mode provides the same configuration options as
IBM 16/4 Token Ring Adapters: 4 IRQ channels and 2 I/O
base addresses. You can continue to use IBM drivers with
the NIC in IBM mode.
Ring Speed
The 3C319 NIC operates at a ring speed of either
4 or 16 Mbps. The 3C319 NIC ring speed must match the
speed of the token ring network. The default value is
16 Mbps. For the NDIS 4 driver, the auto ring speed
detection feature is enabled by default. (To disable the
auto ring speed detection feature, see
“Auto Ring Speed
Detection
” in
Chapter 7
.)
I/O Base Address
In IBM mode when only one 3C319 NIC is installed, it is
designated the Primary NIC. Change the Primary/Alternate
option with the Configuration and Diagnostic Program.
The base address allowed in IBM mode is A20h (primary)
or A24h (alternate). The default is A20h.
In 3Com mode the I/O base addresses designate the
NICs. The I/O base addresses for 3Com mode are as
follows, with the default address in
bold
:
A20h
280h
300h
380h
A24h
290h
310h
390h
210h
2A0h
320h
3A0h
220h
2B0h
330h
3B0h
230h
2C0h
340h
3C0h
240h
2D0h
350h
3D0h
250h
2E0h
360h
3E0h
260h
2F0h
370h
