Xerox 820 II

[Roman Szeremeta]

I'm trying to boot up an old Xerox 820 II with twin 8" floppies.
I get an * (asterix) prompt with two options:-
H Terminal
L Load
When I put the system floopy in drive A: and type L I get an error message 
"A:Load Tables Error". The drive light comes and it spins up but it doesnt 
sound like the drive is actually reading the floppy disk. I get the same 
result with drive b. I worked out that LB: reads the B drive.
Any ideas?
Roman