According to various faqs I've read, Qlogic/ISP ISP1000 based disk controllers including those made by PTI are supported. So, needing to connect some single-ended ultra-wide SCSI disks and needing more I/O than the 10mb/s fast-narrow controller could accomodate, I purchased a PTI SBS450S-10704 SCSI controller and attempted to install it on a Sun 4/670MP running Linux 2.2.13, using a kernel I built which did include the ISP drivers. The probe-scsi-all command saw this controller and all the drives attached fine despite being document as not being supported. When I tried to boot linux, I got the following error: qpti0: IRQ 53 SCSI ID 7 <0>qlogicicpt0: Firmware dload failed, I'm bolixed! Kernel Panic: SBUS Qlogic/ISP firmware load failed. It then proceeded to do the: AIEEE Interupt handler... something or other and then spinlocks... There must be a secret but I don't know what it is. Can anyone enlighten me as to what the magic incantations are that are necessary to get this to work?