Atari CX 5200 Field Service Manual page 55

POKEY (PORT) TEST
Purpose: To determine any port line failures and confirm the correct
•
operation of the POKEY chip.
Procedure: P ress key 5 followed by ST ART.
•
For m at: When you press the keys listed in the first column below , the
•
numbers and letters in the second column should appear on the screen in
the KB column:
KEY
1
2
3
It
5
6
7
8
9
/I
o
*
START
PAUSE
RESET
If the keys do not re gister correctly when
TROUBL ESHOOTING, page ItA-22.
P ress the botto m fire button. The POKEY A DJ U S T screen should disappear .
If it doesn't proceed to page 3 A-9.
P ress key 5 followed by START, again bringing the POK E Y A DJ UST pattern
to the screen.
Repeat Step 2.
RAM TEST
Initialization for RAM
Purpose: To set the 5200 up for a loop test to fully check the R A M ( A I 8-
•
A25).
Procedure: Press key 9 followed by STA RT.
•
Then press key 2 followed by START.
A gain press key 2 followed by S T ART.
DISPL A Y ERR O RS CON TINUOUS TEST appears in the green band on the
screen.
.
RAM Test Procedure
Purpose: To test the functioning of the 1 6K R A M chips.
•
Procedure: P ress key 7 followed by ST A RT .
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CX520 0 Field Service Man ual
KB Readings
1
2
3 NOTE: When using the 1 . 1 Diagnostic
Cartridge to test the 2-PORT 5200 , the
It
5 KB Readings may appear to the right of
6
any of the four ports listed on the screen,
7 besides the port you are testing. They
8 must, however , appear to the right o f the
9 port you are testing for the test to be
D valid.
o
E
A
B
C
Unplug the controller fro m Por t 1 and insert it into Port 2.
Test
3 A -8
pressed, proceed to KEYBOARD