NAME

     aha — Adaptec SCSI host adapter driver

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel
     configuration file:

           device scbus
           device aha

     Alternatively, to load the driver as a module at boot time, place the following line in
     loader.conf(5):

           aha_load="YES"

     In /boot/device.hints:
     hint.aha.0.at="isa"

DESCRIPTION

     This driver provides access to the SCSI bus connected to the Adaptec AHA-154x and AHA-1640
     SCSI host adapters.  x is 0 for controllers without a floppy drive and 2 for controllers
     that have them.  For optimum performance, Adaptec AHA-174x controllers should be configured
     in enhanced mode and attached via the ahb(4) driver.

     One device hint entry for every card to be attached by the system is required.  Specific
     values for the port address, IRQ, and DRQ may be specified.  If wildcard values are used,
     the driver will query the device for its current settings and use those.  If the port
     address is a wildcard, the driver consults an internal table of possible port address
     locations and attaches to the first unattached card it finds.  The possible port addresses
     for this card are 0x330, 0x334, 0x230, 0x234, 0x130, and 0x134.

     The AHA-1640 is an MCA bus card.  Since the MCA bus is a self-identifying bus, no setting of
     hints is required.

HARDWARE

     The aha driver supports the following SCSI host adapters:

     •   Adaptec AHA-154xB
     •   Adaptec AHA-154xC
     •   Adaptec AHA-154xCF
     •   Adaptec AHA-154xCP
     •   Adaptec AHA-1640
     •   Adaptec AHA-174x in 154x emulation mode
     •   DTC 3290 SCSI controller in 1542 emulation mode
     •   Tekram SCSI controllers in 154x emulation mode

SEE ALSO

     ahb(4), ahc(4), aic(4), cd(4), da(4), sa(4), scsi(4)

AUTHORS

     The aha driver was ported by M. Warner Losh from the bt driver written by Justin T. Gibbs.

BUGS

     The AHA-154xA card does not support residuals on data transfers.  As a result, this card is
     no longer supported.

     There have been some reports that the AHA-154xB does not work well under heavy load.

     The AHA-154xCP is a plug and play controller.  However, its resources are set using the on-
     board BIOS and cannot be moved.  Failures to attached for this card are often caused when
     the resources set in the BIOS conflict.