Service
Model
83522A
The address lines can be exercised by performing the Minor Address Decoder
Test. On the
8350A, enter:
SH3F"r
5
4
Minor Address Decoder Test
Verify activity on each of the buffered address lines (BAO
-
BA3).
Data lines can be verified by performing a Data Rotation Write to any address
location between
2COOH and 2FFFH. On the 8350A, enter:
CW
Set 8350A into CW mode
SHIFT
0 0 Enters the Hex Data command
2
GWzs
O
0
Address location 2C00
M4
Hex Data Rotation Write
Check for activity on each of the buffered data lines (BDO
-
BD7), and check
for shorts between lines.
Interrupt Timer/PIA
The PIA is responsible for two functions:
Reading the Configuration Switch
Routing the
L
SIRQ Interrupt from the A6 Assembly
NOTE
Before changing the Configuration Switch settings, note the
switch positions and return the switches to their. original
settings after troubleshooting.
The PIA's read capability can be checked by entering:
Sets the
8350A into CW mode
Enters Hex Data command
Address location 2900
Hex Data Read
Watch the display change as the Configuration Switch is toggled.
The Triple Timer and
PIA's interrupt masking capability are tested using a
special routine at INSTR PRESET or power-on. Error Codes E052 or E053 are
displayed if a failure is detected. If these error codes are found, or if either
U4
or
U5 are suspect for other reasons, a special test pattern can be accessed by
entering:
SHIFT
5
5
Interrupt Control Test
The waveforms shown in Figure 8-22 should be observed. Refer to "Other Error
Codes" for details on these errors codes and the
SHIFT
5
5
Operator
Initiated Self Test.
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