By default, a Gateway 2000 computer has a bus speed of 12 MHz,
which must be changed to 8 MHz by setting the appropriate jumpers
on the motherboard. Once the bus speed has been set to a lower
value (8 MHz), the 3C603 Token Link card will work correctly, and
so will OS/2 or DOS LAN Manager.
The reason the bus speed must be changed is that all ISA net cards
are designed to run with a bus clock of 6 to 8.333 MHz. Therefore,
a higher (or different) bus clock frequency will affect all ISA
devices in an unspecified manner.
EISA devices (net cards) are designed to handle higher bus clock
frequencies (up to 33 MHz).