29 Mar
2006
29 Mar
'06
2:48 p.m.
Tony wrote...
YEs, although DEC never actually considered you might do that. From what
I've read, all 11/45 CPU backplanes were made with the jumper. You cut it
if you put in the KW11-L card (M787). But yes, you re-fit the jumper if
you want to pull that card and carry on running.
It's not just 'if you want to use a clock
on a DL11-W'. That jumper
completes the grant chain for one of the bus grant sigals (the one that
is used by the line time clock interrupt), if you miss it out, then _no_
device on that priority level can interrup. It's like missing out a grant
continuity card.
I took it as "if you want to yank out the M787 from a system
that previously
had one. You can check with an ohmmeter that those 2 pins
are connected to see if
the jumper is in place.
I checked, I do have that jumper.