Diagnostics and System Management Services 171
individual subsystems, one of the icons will be the memory icon. During the
display of this icon, an 8-digit error code will be displayed if the L2 cache is
not fully functional.
The remainder of memory is also tested, and if a failure is detected, an 8-digit
error code is posted. This error indicates which Dual Inline Memory Module
(DIMM) slot is at fault. The basic algorithm for the system memory
configuration is as follows:
1. Query each memory slot to see if there is a memory DIMM installed.
• If yes, determine its size. Identify each DIMM as IBM or non-IBM, ECC,
or parity. This is done by querying special identification registers in the
DIMMs themselves.
• If the DIMM could not be identified, display the memory slot number, as
well as a warning saying that a DIMM could not be identified. Proceed
with the next DIMM.
2. Test the DIMM.
• If this is an IBM DIMM and it passes the test, make it available and add
its size to the available memory quantity. If it does not pass the test,
keep the DIMM out of the system configuration and display a warning
on the screen reporting the faulty DIMM slot number.
• If this is a non-IBM DIMM and passes the test, make it available and
add its size to the available memory quantity. In addition, display a
message on the screen reporting that a non-supported, non-IBM
memory DIMM has been found, tested, and correctly configured. If the
DIMM does not pass the test, display a warning on the screen reporting
that a non-IBM memory module was found and failed to pass the test.
3. Proceed with the next DIMM.
At the end of this process, the system will have available all the memory it
could configure (IBM branded or not).
6.6.3 Graphics Adapter POST
The firmware tests the graphics adapter but not the display. The system will
give a speaker beep sequence when the graphics adapter is found to be
non-functional. The beep sequence is one long beep, followed by one short
beep. The error is logged, and the system boot continues.