cac —
Compaq array controller driver
cac* at eisa? slot ?
cac* at pci? dev ? function ?
The cac driver provides basic message passing and DMA
  support for Compaq array controllers. Disk arrays are supported by the
  ld driver. Monitoring of volume status is supported
  through the bioctl(8) and
  envstat(8) utilities, as well
  as the powerd(8) monitoring
  daemon.
The cac driver provides support for the following
  controllers:
  - Compaq Integrated Array
-  
- Compaq IAES
-  
- Compaq IDA
-  
- Compaq IDA-2
-  
- Compaq RAID LC2
-  
- Compaq Smart Array 221
-  
- Compaq Smart Array 3100ES
-  
- Compaq Smart Array 3200
-  
- Compaq Smart Array 4200
-  
- Compaq Smart Array 4250ES
-  
- Compaq Smart Array 431
-  
- Compaq SMART
-  
- Compaq SMART-2/E
-  
- Compaq SMART-2/P
-  
- Compaq SMART-2DH
-  
- Compaq SMART-2SL
-  
 
The cac driver first appeared in NetBSD
  1.5. Support for volume monitoring through
  bio(4) and
  envsys(4) was added in
  NetBSD 5.0.