System Control Panel Sw Itches And Lamps - HP 3000 III Series Manual

Sys tern Ve r if ica tion and
'It
oub leshoot ing
Table 3-1. System Control Panel Switches and Lamps (Continued)
Sends the contents of memory and
CPU registers to the system mag-
netic tape unit.
RUN/HALT (switch)
SYSTEM HALT (lamp)
ENABLE (sw itch)
DUMP (switch)
LOAD (sw itch)
-------------------------T-------------------------------------1
Panel
Marking
Function
1
1 1
------------------------- -------------------------------------1
Indicates a system halt caused by
I
an irrecoverable error detected by
1
the firmware.
1
1
Re ve r se s th e r un /ha I t cond i t i on of
1
the sys tern.
1
I
Must be he ld in the ENABLE pos i tion
I
to permit the LOAD or DUMP switch
1
function to become active.
1
1
1
1
1
1
Used to load memory from a device
1
specified by the SYSTEM SWITCH
I
REGISTER contents.
1
1
- . . . . . . . · _.... --.....· . . . . . . . _· ...._c__._·_... __
3-8. MAINTENANCE PANEL
The Maintenance Panel (figure 3-2) is a troubleshooting aid for
the computer system. When the panel is connected to the system,
switches on the panel are used to select specific registers whose
content may be observed or changed to assist in localizing system
faults. Additionally, lamps on the panel show the contents of
many computer registers and the state of principal signals, al-
lowing analysis of system functioning. (For the most part, the
visual displays are used only when the computer is halted.) Op-
erating power is provided by the computer system. An interface
PCA, installed in the CPU card cage, is required for the Main-
tenance Panel.
The names of switches and indicators on the Maintenance Panel are
marked on an overlay which installs on the face of the unit. A
smaller overlay (the I/O overlay) can be placed over a certain
row of lamp names on the main overlay to extend the display func-
tion of those lamps. A switch permits display of the signals
named on the small overlay; other displays remain unchanged. The
small overlay can be turned over to provide another set of names;
these signals are displayed by making an additional cable connec-
tion to the computer. The Maintenance Panel also has a self-test
capability which allows the operability of most panel circuits to
be verified without the use of test equipment.
3-4