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B-28 Backdating
Sub
Decoder
GPIA CS
Keyboard
LB
ADD
READ
LATCH l
HP-IB
RAM-SEL
Table B-5. Sub Decoder Signature Analysis
Free Run UlO U l l U13 U14 U15 Ul6 UIS U19 U23 U26 U30 U37
S.A.
Pin Pin Pin Pin Pin Pin Pin Pin Pin Pin Pin Pin
748C
7
3
U638
10
7
89C7
14
1 1
C898
12
1 1
6P25
1 1
1 / 1 9
HCSA
10
1 1
PHCC
7
9
8UP9
8
8
5HP5
15
9
OASU
14
10
H883
13
1 1
9.
In Chapter
10.7
modify the section on trouble-shooting the ROM
as follows:
ROM
The ROMs can be checked using signature analysis:
1 .
Set the microprocessor to free-run as described in Chapter
10. 7
and connect the signature analyzer probes as instructed.
Signature Analyzer Probe connections for ROM Test
Probe Trigger
Connect to
Start
\
See Table B-6
Stop
f
See Table B-6
Clock
\
TP "E"
Ground
Ground
2. Connect the data probe to the +5
V
supply and check that the
signature is P254. If not , the microprocessor is not free-running.
Summary of Contents for 8112A
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Page 144: ...8 32 Testing Performance ...
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Page 240: ...10 4 16 Servicing the Shaper and Output Amplifier ...
Page 242: ...A R l BD RY MR I N 1 2 7 I I IJt 51 CR1 B e i 1 _ _ _ _ 20 ...
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Page 262: ...A B A2 ED RY CONTROL ...
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Page 290: ...R B c R3 BD RY M I CROPROCESSOR 1 2 3 FIGURE 1 0 7 8 ...
Page 294: ... 8 X2l 2 X2 Figure A 1 Mechanical Parts 1 A 2 Replaceable Parts ...
Page 295: ...MP MP3 MP MP2 MP4 MPS MP 1 2 MPS MP MP I B ElElElEl Replaceable Parts A 3 ...
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Page 378: ...Figure B 14 Mechanical Parts 1 B 44 Backdating ...
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