EO(4) BSD Programmer's Manual EO(4)NAMEeo - 3Com EtherLink (3C501) Ethernet interface
SYNOPSIS
eo0 at isa? port 0x320
DESCRIPTION
The eo interface provides access to a 10 Mb/s Ethernet network. It uses
a jumper-selectable block of 16 i/o ports in range 0x200 through 0x3f0.
The block must be aligned on a 16 port boundary. The jumper-selectable
hardware interrupt level is detected at autoconfiguration time or alter-
natively can be specified in the kernel configuration file. The 3C501
supports the following irqs: 2(9), 3, 4, 5, 6, 7; it can be installed in
8-bit or 16-bit slot. DMA is not supported in the standard driver, but a
compile flag turns it on for use with very old 3c501s. In this case the
DMA channel should be selected by the on-board jumpers and specified in
the system configuration file. Supported drqs are: 1, 2 and 3.
Each of the host's network addresses is specified at boot time with an
SIOCSIFADDR ioctl. The ef interface employs the address resolution pro-
tocol described in arp(4) to dynamically map between Internet and Ether-
net addresses on the local network.
MEDIA SELECTION
The type of interface (10BASE-2/BNC or AUI/DIX) is selected manually by
the on-board jumpers.
DIAGNOSTICS
The following diagnostics may be printed during autoconfiguration:
eo%d: invalid i/o base address %x
Invalid port specification in kernel config file.
eo%d: invalid IRQ number %d
Invalid irq specification in kernel config file.
SEE ALSOintro(4), inet(4), arp(4)BUGS
Usage of this Ethernet interface card is not recommended because of se-
vere performance problems and loss of packets when it is used to communi-
cate with machines equipped with faster Ethernet interfaces. This card is
no longer manufactured.
HISTORY
The eo driver first appeared in BSDI.
BSDI BSD/OS October 9, 1992 1