Steve Woodford writes: 

> It's a bug in the bootloader. Booting from tape is not well tested these
> days, mainly because my aging Archive Viper 150 is on its last legs...

I'd be more than happy to help you with this, if you can take a bit of time 
to educate me as to how the bits fit together.  I actually have a Viper 150 
as well as the Tandberg. 

> Replace the `stboot' file from the snapshot with the one attached to this
> email. I've hand-patched it to work around the bug.

Better, but now we have a new issue.  With that stboot, and the 20010807 
snapshot bootst & netbsd-rd, I get: 

177-Bug>bo 0,30
Booting from: VME177, Controller 0, Drive 30
Loading: Operating System 

Volume: NBSD 

IPL loaded at: $003F0000 

NetBSD/mvme68k MVME177 tapeboot [1.3] 

978429=0xeef9c
Start @ 0x8000 [1=0xf6e00-0xf6f9c]...
Exception: Illegal Instruction
PC =00008004 SR =2700
Format/Vector =0010
PC   =00008004 SR   =2700=TR:OFF_S._7_....   VBR  =00000000
SSP* =003EFF70 USP  =00010000 SFC  =1=UD     DFC  =1=UD
CACR =00000000=D:....._B:..._I:...           PCR  =04300500
D0   =003EFF31 D1   =003EFF31 D2   =00000000 D3   =00000000
D4   =49504C2C D5   =00000000 D6   =00000000 D7   =00000000
A0   =00008000 A1   =003F1C13 A2   =003F1754 A3   =00000000
A4   =00000000 A5   =00000000 A6   =003EFFC4 A7   =003EFF70
00008004 000E              DC.W        $E
177-Bug>