Control Data Corporation CDC CC63X Hardware Maintenance Manual page 55

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• Graphics Bulk Write - If this option is present, a bulk
write of zeros will be output to the graphics RAM. If the
bulk write busy status does not set and clear, the message
GRAPHICS FAIL will be displayed. If the graphics RAM does
not contain all zeros, the message GRAPHIC FAIL will be
displayed .
• ROM Test - A checksum is run on each memory chip of the
resident ROM. A failure of this test displays ROM FAIL XX
XX XX. The first value is ROM I, the second is ROM 2, and
the third is ROM 3. A value other than 00 indicates the
failure location.
• NVM Test - A checksum is run on the nonvolatile memory
(NVM) , and if an error occurs, either NVM ALTERED or NVM
FAIL displays. The NVM ALTERED message applies to
terminals having the enhanced firmware and the message NVM
FAIL applies to terminals that do not have the enhanced
firmware.
•
•
Loopback Test - The test is comprised of transferring 128
characters from the processor to the corrununications UART,
which is conditioned to echo rather than transmit all
data. The data is tested as it is received. Transmitter
speed is fixed at 9600 baud. A failure of the test will
display COMM FAIL on the next line of the CRT. The same
test is conducted on the UART to the keyboard. A failure
of this test will display the message KEYBOARD FAIL on the
next line of the CRT.
Timer Test - The timer will be started for a 5-millisecond
delay with the timer interrupt enabled. If a timer
interrupt does not occur before 6 milliseconds, interrupts
will be disabled and the message TIMER FAIL displayed.
• Battery Test - This test will sample the battery low
status. If the battery voltage level is low, BATTERY LOW
will be displayed. This is not an error condition, but
indicates battery should be replaced before NVM is lost.
• Serial Ports - If this option is present, this test will
test both ports A and B which are conditioned to echo
rather than transmit all data. The data is tested as it
is received. Transmission speed is fixed at 9600 baud. A
failure of the test will cause a display of PORT A or PORT
B FAIL.
• Test Switch - The position of the TEST switch on the rear
panel will be tested. If enabled, the message TEST SWITCH
ENABLED is displayed. In addition, the keyboard clock is
tested and the message KBD CLOCK FAIL displays if it is
defective. Also, the keyboard loopback test is run in
external mode and the message EXT KBD LOOPBACK FAIL
displays if a failure occurs.
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