Can't boot Digital Unix from HDD or CDROM on Digital Workstation 433au

[T.S.]

Hello I am having difficulty booting an old Digital Workstation 433au server running Digital Unix v4.0c.

After a recent power-down the machine will no longer boot from the HDD or from the CDROM. Attempting to boot from the HDD produces the following message.

>>>boot
(boot dkc0.0.0.1004.0 -file vmunix -flags A)
block 0 of dkc0.0.0.1004.0 is not a valid boot block
bootstrap failure
>>>


Given that all the boot environmental variables appear to be correct I assumed that the root partition had been corrupted and attempted to boot from a Digital Unix v4.0c CDROM. This appears to work at first, hvmunix is loaded, and the machine appears to begin loading devices, however the boot process then stumbles and produces the following error (i've included a bit of the output before the error as well).

...
tu0: auto negetion off: selecting 10BaseT
(UTP) port: half duplex
ata0 at pci0 slot 7
ata0: Cypress 82C693
panic (cpu 0): pyxis_intrdsabl: int out of
range

DUMP: No primary swap, no explicit dumpdev. Nowhere to put header, giving up.

halted CPU 0

halt code = 5
HALT instruction executed
PC = fffffc0000405c10

I know the CDROM works since I have used it to boot a second identical but healthy server, additionally I know the CDROM drive is OK since I swapped drives between the healthy server and this one. Any recomendations what to do here?

Any help would be greatly appreciated.

Thanks

Taylor.
>>>

[Vladimir Fabecic]

As far I can remember pyxis_intrdsabl is something about hal.
Maybe power-down did some damage to machine
Can you see all devices in SRM normally?
Can you post output of:
>>> show device
>>> show config

[Pieter 't Hart]

Even when you boot from CD TRU64 tries to read the HW-config from the bootdisk defined in the environment variable bootdef_dev.
You may clear this variable to prevent CD-boot from trying to read the config from bootdef_dev.

>>> clear bootdef_dev

Pieter