6.6 Digital LEDs for Status Indication
The Digital LEDs for Status indication are used for displaying a POST code at system startup.
It also displays an error code that occurred during system operation.
It should be noted that the Digital LEDs for Status indication may display a code even when
there is no error.
(Example: when the BIOS setup menu is displayed: Ab, POST code for power on until OS
As shown below, the numerical value lamp shows the digits from 0 to F hexadecimally.
6.6.1 POST messages
Power On Self Test (POST) is a function whereby the system BIOS makes routine checks
for hardware failure when the power of the computer system is turned on. If any failure is
found, the POST code corresponding to the location of the failure is displayed on the Digital
LEDs for Status indication situated on the front of the equipment.
In this equipment, a POST code is displayed in the following cases:
(1) Main memory is not installed.
POST code "53" is displayed with a beep.
(2) The BIOS setup menu is being displayed.
POST code "Ab" is displayed.
(3) The OS starts.
POST code "A0" is displayed.
If RAS software is installed, the digital LEDs for status indication go out after indicating
If RAS software is not installed, the digital LEDs for status indication remain to indicate
(Note) If the user's tool and a device driver write in "80h" of I/O space, a display code