The aic module can be configured for disk and streaming tape support for one or two host adapter boards, each of which must be the sole initiator on a SCSI bus. Autoconfiguration code determines if the adapter is present at the configured address and determines what types of devices are attached to the adapter.
If multiple boards are configured in a single system, each board must occupy a different I/O base address in the system I/O address space. Each board must also be assigned a different IRQ level.
The AHA-1522 or AHA-1520A controller can be used as a primary boot controller only at I/O base address 0x340 (unless special BIOS from Adaptec is procured). Therefore, if a system installation is performed using a SCSI device (such as a CD-ROM drive) connected to one of these adapters, the adapter must be configured with I/O base address 0x340. (The adapter BIOS supports booting from this address only.)
Refer to the AHA-1520A/1522A AT-to-SCSI Host Adapters Installation Guide provided with the controller for instructions on installation of the adapter and the valid jumper settings. The default jumper configuration described in the AHA-1520A/1522A AT-to-SCSI Host Adapters Installation Guide is the recommended configuration for the controller.
The aic driver does not support SCSI timeouts.