This is an experimental SCSI driver for the Future Domain 18c30 (now Adaptec AHA2920) SCSI controller series. The driver has been contrib- uted by Michael Ranner , who assembled it from pieces of the PAO distribution. This driver uses a different low-level SCSI interface than normal FreeBSD SCSI drivers that sneaked in from NetBSD via PAO. This is the main reason why I (joerg) never could make up my mind to import it into the main FreeBSD tree; the code duplicates some of the existing FreeBSD code in functionality, and it ``doesn't quite fit'' into the remaining framework. However, the driver basically works, so I figured it would be a useful addition to the /xperimnt section of the FreeBSD 2.2.5 CD-ROM. The only observed bug so far is that it totally jammed in a machine wiht a dead TMC18c30 controller (even though it detected the hardware fail- ure of the controller). To install the patch, do the following: cd /usr/src mkdir sys/i386/scsi/tmc18c30 sys/i386/scsi/scsi_low zcat /cdrom/xperimnt/aha2920/tmc18c30-sysdiff.gz | patch After patching, you'll find a file /sys/i386/conf/GENERICAHD that is a regular GENERIC kernel config file, with the `ahd' controller added. I'm also providing an untested installation floppy in this directory, which has been built using the 2.2.5-BETA sources from Oct 13, 1997, with this patch applied. Dresden, October 15, 1997 Jörg Wunsch