Computer Self-Test; Fault Indicators - Data General NOVA 4/S Manual

Data General Corporation (DGC) has prepared this manual for use by DGC personnel and customers as a guide to the proper installation, operation, and
maintenance of DGC equipment and software. The drawings and specifications contained herein are the property of DGC and shall neither be reproduced in whole or
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CHAPTER 5
COMPUTER SELF-TEST
Whenever the computer is powered up, the CPU
automatically runs a 4-second self-test to ensure that
the computer can load and run diagnostic programs.
(The CPU also runs this test after a power failure when
battery backup is not present.) The self-test consists of
several ROM-resident diagnostic tests which check the
operation of the power supply, the system terminal, the
basic CPU functions, and the first 32K bytes of
memory. As the CPU completes portions of the self-test
it prints (displays) part of the following message on the
OK
1000000
'
The last exclamation point (!) is the VC prompt.
If the entire message is printed, all the diagnostic tests
have run and the self-test is successfully completed. If
only part of the message is printed, the self-test found a
bad unit. The indicator lights on the front console
together with the printed part of the message indicate
the probable faulty unit, as shown in Table 5.1.
FAULT INDICATORS
Power Run Light Message Fault Indicated
Light Printed on
Off On or off Power supply
On On for 1 sec Basic CPU
On Flashes on System terminal
once*
On Off oO Memory