Service manual

Power-Up 2-21
The continuation of Example 2–1 shows the description of each QBB. In this
particular system only QBBs 0 and 1 have local I/O risers. QBB1 has two CPUs
while the rest have four. Other similarities and differences between the QBBs
can be seen by further examination.
QBB0 is described.
QBB1 is described.
QBB2 is described.
11
QBB3 is described.
12
The SCM can now begin to monitor the state of the OCP switch.
Once the SCM has configured the CSB, it begins to monitor the state of the
OCP switch. Assuming the switch is in the Off position, the SCM monitor
display remains at the SCM prompt. If the OCP keyswitch is in the On
position, the SCM will automatically continue with power-up.