---
name: "sm"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/sm/4"
---

# sm(4)

SMC91C9x and SMC91C1xx-based 10/100 Ethernet device

## NAME

**sm** – SMC91C9x and SMC91C1xx-based 10/100 Ethernet device

## SYNOPSIS

**sm0 at isa? port 0x300 irq 10** **sm\* at pcmcia?** **nsphy\* at mii?**

## DESCRIPTION

The **sm** device driver supports SMC91C9x and SMC91C1xx-based Ethernet interfaces.

The ISA attachment of the **sm** driver supports any SMC91C9x-based Ethernet interface on the ISA bus, including the EFA Info\*Express SVC VLB interface, and the on-board SMC91C9x Ethernet found in many embedded PCs and laptop docking stations.

The PCMCIA attachment of the **sm** driver supports Megahertz X-JACK Ethernet cards, NewMedia BASICS Ethernet cards, and SMC EtherEZ 8020 series cards.

## MEDIA SELECTION

The SMC91C1xx supports the following media types:

- autoselect

  Enable autoselection of the media type and options. The user can manually override the autoselected mode by adding media options to the appropriate [hostname.if(5)](/hostname.if/5.md) file.

- 10baseT

  Set 10Mbps operation. The *mediaopt* option can also be used to select either *full-duplex* or *half-duplex* modes.

- 100baseTX

  Set 100Mbps (Fast Ethernet) operation. The *mediaopt* option can also be used to select either *full-duplex* or *half-duplex* modes.

The SMC91C9x supports AUI and UTP media types:

To enable the AUI media, select the *10base5* or *aui* media type with [ifconfig(8)](/ifconfig/8.md)'s ‘media’ directive. To select UTP, select the *10baseT* or *utp* media type.

For more information on configuring this device, see [ifconfig(8)](/ifconfig/8.md).

## DIAGNOSTICS

- sm0: unable to read MAC address from CIS

  This indicates that the Ethernet address, which is stored in the CIS information on the Megahertz X-JACK PCMCIA Ethernet card, is corrupted.

## SEE ALSO

[arp(4)](/arp/4.md), [ifmedia(4)](/ifmedia/4.md), [intro(4)](/intro/4.md), [isa(4)](/isa/4.md), [netintro(4)](/netintro/4.md), [nsphy(4)](/nsphy/4.md), [pcmcia(4)](/pcmcia/4.md), [hostname.if(5)](/hostname.if/5.md), [ifconfig(8)](/ifconfig/8.md)