Anyway, does anyone have experience of rack-mounting a
TU56? It clearly
 doesn't go on slide rails, it bolts directly to the rack (hinge down
 the front
 panel for access). I have the manuals from Bitsavers, they imply there
 is some
 kind of spacer block that goes under the TU56. Does anyone know what
 that
 is exactly so  I can attempt to make one if it is needed.
 -tony 
I mounted my TU56 in an H960 recently(ish). The block you mention only acts
as a support while you bolt the TU56 in and isn't needed afterwards. The
TU56 is too heavy to easily support with one hand while you put in a couple
of bolts - the manual advises separating the front panel and reassembli8ng
after mounting but that seems more bother than it's worth. I bolted a piece
of scrap across the H960 to hold the TU56 up while I put the bolts in.
5-minute job.