Hi,

   I use a unix box with a 'portable' TK50 SCSI drive to write the
   bootimages to the tape, then load the tape in the MVAX (which
   has a built in TK50 -this as overkill info-) and boot it with 
   >>> b /3 mua0
   
   The result is after a minute or so:
   
   ?4B CRLERR, MUA0

Someone else (Ragge?) saw something similar when they tried to do a tape
boot on a TK70. (Unfortunately we don't know what causes it yet:-) The
TK50 is only one density, so density selection shouldn't (?) be an issue
unless it's a TK70. The only thing I can suggest is to make sure you
write the file to tape in 512byte blocks. (I do know that bigger blocks
confuse the console boot.)

Good luck and let us know if you get it working, rick