Adaptec SCSI Driver unable to find SCSI adapter or hangs on the start.
Description: During the start of Adaptec driver ASPI8DOS.SYS hangs. Alternatively, Adaptec driver ASPI8DOS.SYS seems to hang for very long time (2-5 mins). Then following error is reported:
'Unable to find any AIC-78xx/AIC-75xx
ASPI8DOS installation failed'
Explanation: Such problem usually means that selected IRQ (by default 11) doesn't work. It's usually due to one of two problems:
  1. Improper Interrupt mode

    Several CardBus adapters allow different hardware implementations for IRQ routing. If you are using any recently manufactured notebook, there is a good chance that correct interrupt mode is properly set by the BIOS. If you are using old notebook or desktop, you may need try various versions of /IM switch to find proper interrupt mode. Exact values for /IM switch are adapter depended.

  2. Improper PCI IRQ routing by BIOS

    The BIOS usually pre-program routing of the IRQ from every particular PCI slot to certain IRQs. Those routings are stored in BIOS inside so called PCI IRQ routing table. In our experience on many machines the PCI IRQ routing table is incorrect or/and incomplete. The PCI BIOS provides an API that allow update PCI IRQ routing table, if required. Unfortunately in many system updating of the routing table when CardBus card is inserted may cause end-less interrupt and hang the system.

    By default, APA-1480 enabler doesn't try modify the routing table if required routing is already in the table. You may force unconditional update of PCI IRQ Routing table using the /FI switch to APA-1480 enabler command line. If after adding /FI switch system appear to hang during APA-1480 enabler load, we recommend to remove the /FI and simply try to find working IRQ by trying.

Solution: Check selected interrupt mode.

Use /PI:n to change used IRQ number. Try different values for n (usually in following order: 11, 10, 9, 5, 7, 3, 4) until you found the working combination.