Apart from a functioning driver, a special firmware is apparently also required to allow Power Macintosh computers to boot from a hard disk drive connected with a SCSI controller in one of the PCI slots. To allow a computer to boot an operating system from a device connected to a PCI card, this means, of course, that the card?s firmware must be loaded even before the operating system is being started. I think that among other companies Adaptec specialized in the production of bootable and non-bootable SCSI cards for Power Macs. Not all of Adaptec?s PCI SCSI cards let Macs boot from attached hard disk drives, for some of them were preferably used to connect scanners or similar devices!

AFAIK Adaptec sold SCSI cards for PCI slots in versions for Power Macintosh computers, whilst other revisions of the same cards could only be used in x86 systems, for there were differences in firmware revisions. Needless to say that those SCSI cards suitable for Macs were more expensive;)

I guess this is similar to the issues with different firmwares for graphics cards, with PC and Macintosh versions available.


Here you can find information concerning Adaptec SCSI cards in PowerMacs:

http://www.macintouch.com/bg3adaptec.html


Well, e.g. the Adaptec 2930 would now be an option to you regarding its "bootability". Yet, it seems that MorphOS does not offer a driver for it(?), for here is a comprehensive list of SCSI adapters supported by this operating system:

http://www.morphos-team.net/hardware.html



> But what prevents the driver for SCSI cards from functioning once a Powermac is booted from an ATA drive?

I could imagine that a PCI card?s firmware revision which is missing or not corresponding with a particular mainboard might prevent the driver for SCSI cards from functioning.


Please, let us know if you are successful with a particular SCSI card, booting MorphOS from it on a PowerMac.