sbni(4) Granch SBNI12 leased line modem driver


device sbni


The driver provides support for leased line modems of following models:

  • SBNI12-02, SBNI12D-02
  • SBNI12-04, SBNI12D-04
  • SBNI12-05, SBNI12D-05, ISA and PCI
  • SBNI12-10, SBNI12D-10, ISA and PCI

and a kit for data link over a voice band:

  • SBNI12-11, SBNI12D-11, ISA and PCI.

In addition to the standard port and IRQ specifications, the driver also supports a number of flags which can set baud rate, receive level, and low three bytes of Ethernet MAC-address (high three are always 00:ff:01 ) because Granch modems are presented to the system as Ethernet-like network cards.

The high byte of the flags is a bit field, it is used to specify SBNI adapter receive level/baud rate:

"Bits 0-3:"
receive level (0x00..0x0f)
"Bits 4-5:"
baud rate number:

"00 -"
0 baud rate (2Mb in fast mode/500kb in slow)
"01 -"
1 baud rate (1Mb/250kb)
"10 -"
2 baud rate (500kb/125kb)
"11 -"
3 baud rate (250kb/62.5kb)

"Bit 6:"
use fixed receive level

if bit 6 is set then receive level will be set according to bits 0-3 value, otherwise receive level will be autodetected

"Bit 7:"
use fixed baud rate

if bit 7 is set then baud rate will be set according to bits 4-5 value, otherwise baud rate is set to 2Mb


The sources for the driver reside in:



The device driver first appeared in Fx 4.6 .


An -nosplit The device driver for Fx 4.x was written by An Denis I. Timofeev , partially based on An David Greenman Ns 's ed(4) driver. Earlier versions (available on were written by An Alexey V. Zverev .

SBNI12 hardware was designed by An Alexey V. Chirkov .