3Com 3C319 manual Ring Speed, Base Address, A20h

5-8CHAPTER 5: CONFIGURING THE NIC MANUALLY

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