These are bootkernels with full scsi support, including the new Future Domain
BIOS version 3.4. From the fdomain.c source:

 The following BIOS versions are supported: 2.0, 3.0, 3.2, and 3.4.
 The following chips are supported: TMC-1800, TMC-18C50.
 Reports suggest that the driver will also work with the TMC-18C30 chip.
 The support for the version 3.4 BIOS is new, as of March 1994, and may not
 be stable.

These are all the included SCSI drivers:

Adaptec AHA152X, Adaptec AHA1542, Adaptec AHA1740, Generic NCR5380 SCSI,
PAS16 SCSI, Seagate ST-02 and Future Domain TMC-8xx SCSI support,
Future Domain 16xx SCSI, UltraStor SCSI, 7000FASST SCSI

You may need to install kernel images from the Q (Alpha 1.1.x series) to boot
your system after installing with these bootkernels. 

These kernels (and this directory) will only last as long as it takes to 
bring all the bootdisks up to this kernel level. If we're lucky, that won't
be all that long. :^)

--- Pat