AHB(4)

NAME
ahb - Adaptec EISA SCSI host adapter driver

SYNOPSIS
controller ahb0 at isa? bio irq? vector ahbintr
controller scbus0 at ahb0

DESCRIPTION
This driver provides access to the SCSI bus connected to an Adaptec 174x hostadapter in either “standard” or “enhanced” mode. If the controller is set to standard mode (using the EISA configuration utility), the driver will automatically switch the card to enhanced mode during the device probe.

N.B.: When configuring a system with both aha(4) and ahb drivers, the ahb driver should be listed first in the kernel configuration file. This ensures that the ahb driver will find the Adaptec 174x boards before the aha(4) driver probes for Adaptec 154x boards.

Note that no I/O addresses are configured in the kernel config file. The 174x uses EISA slot-specific I/O which is configured automatically.

SEE ALSO
aha(4), ahc(4), cd(4), scsi(4), sd(4), st(4)

AUTHOR
The ahb driver was written by Julian Elischer for Mach 2.5. It was converted to automatic EISA configuration by Justin Gibbs.

HISTORY
The ahb driver first appeared in the 386BSD patchkit.