Z$OQT
If the result of a self test,
or
any other mainframe
operation
produces a pod
timeout
message, the pod
is
considered to be inoperative. Troubleshoot an
inoperative pod as described
under
the heading Troubleshooting an Inoperative
Pod. Select a suitable UUT as described
under
the
heading
Selecting a UUT for
Pod Testing.
N
0
TE
The
pod
timeout
message can also
resultfrom
stuck UUT
forcing
lines which can disable the
pod.
Forcing lines can be disabled
during
mainframe setup
procedures
as described in the mainframe
manual.
5-7.
Selecting a
UUT
for
Pod Testing
In
order
to
troubleshoot
a pod, a known-good UUT must be connected
to
the
pod via the
ribbon
cable and connector. The UUT may be any device which
normally
employs a Z80 microprocessor and to which power can easily be
applied. The UUT
is
needed to provide the following functions during pod
testmg:
0
RAM
and ROM for performing
read/
write
operations
0
Z80 compatible clock signal to drive the pod
0
+5V
dc UUT power
to
check the UUT power sensing circuit
Instead
of
connection to a known-good UUT, the
ribbon
cable connector may
be
connected to the selftest socket on the pod. The self test socket provides a Z80
compatible clock signal,
+SV
dc, and also simulates ROM by connecting the
high
order
address lines back to the
data
lines (refer to the schematic diagram for
details).
However, insertion of the
ribbon
cable
connector
directly
into
the selftest socket
places pin
29
at ground. The pod senses the
ground
at pin
29
and notifies the
mainframe
of
the selftest connection. As a result, the mainframe inhibits normal
operation
and only allows self testing.
During
pod
troubleshooting
procedures, normal mainframe operation must
be
allowed. Consequently, the pod must be prevented from sensing the ribbon
cable
connector
in the self test socket.
To
prevent the pod
from
sensing the self
test connection, pin
29
of the connector must
be
effectively removed.
To
effectively remove pin
29
of
the
connector, obtain
a 40-pin IC socket or
connector
and modify it as follows:
1.
Remove pin
29
from the IC socket.
5-7
Содержание 9000A-Z80QT
Страница 6: ......
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Страница 18: ...ZBOQT Figure 2 3 Connection 0 Interface Pod to UUT...
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Страница 76: ...Z8OQT MP10 H 2 9000A Z8OQT 5071 Figure 6 1 9000A 2800T Intertace Pod Final Assembly...
Страница 84: ...Z8OQT E 3 mwmdwwwwmi o a u n v u 2 as MLVLSI IQ 23333329...
Страница 85: ...ZBOQT QLVLSNXVI 9 Figure 7 1 A11 Processor PCB Assembly...
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Страница 88: ...2800T 7 6 m V L LOl D INPUTS PAL U27 LOGIC Flgure 1 1 A11 Processor PCB Assembly cont OUTPUTS 15...
Страница 89: ...ZBOQT DEVICE 6ND PINS 14 Figure 7 1 A11 Processor PCB Assembly cont 7 7...
Страница 90: ...Z8OQT LA SELF HOLD LO BUSAK 7 8 C 2 5 5v 22A if 22L l clz Em 0531 00 463 EEF tzaF L _____________ _J...
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