Avanti supports Digital UNIX V3.2C and later, including the later releases named Tru64 UNIX. This is the guest-family support boundary, not a claim that every installation kit, hardware-update kit, virtual-device combination, or pre-release has been qualified with every Avanti release.

OSF/1 V1.2 and V1.3A predate the AlphaServer 400 and are outside the supported guest matrix. Some V3.2 hardware-update kits initially identify their V3.2C base system; record the installed version after applying the update rather than treating the kit filename as the running version.

Digital UNIX V4.0D and earlier do not support the KZPCA wide SCSI controller on the emulated AlphaServer 400. V4.0E has not been qualified for KZPCA and is not part of the current KZPCA support claim. Use KZPAA for those releases. The supported KZPCA matrix starts at V4.0F, for which runtime testing covers boot and storage I/O.