> [1] Edit arch/alpha/pci/sio_pic.c and take out the define for
>   BROKEN_PROM_CONSOLE (or make it xxBROKEN_PROM_CONSOLE)

Working.  Many thanks. 


> [2] Update your SRM; and in fact update all three of your machines
>   with the exact same SRM image. Then see if the one machine (or

The confused machine says "V6.8-44 Jul 28 1998 16:01:59".  So does 
one of the happy machines.  I didn't check the 3rd. 

These machines only arrived here a month or so ago.  I hope they 
are up to date.  (They were new rather than recycled.) 

I scaned the firmware section on www.digital.com.  6.8 was the latest 
I could find.  (I admit I stopped looking after I found it.  I found 
various older versions but no hints of anything newer.) 


> [3] Does Digital Unix (or VMS) work on that box?

Digital Unix works fine.  (on all 3 machines)