Acer Aspire 4743Z, Service Manual

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Troubleshooting
4-29
0xC9 pretask before EISA init LBT Core
0x51 EISA Init LBT Core
0x5A Display prompt "Press F2 to enter SETUP" LBT Core
0x5B Disable CPU cache. LBT Core
0x5C Test RAM between 512K and 640K. LBT Core
0x60 Determine and test the amount of extended memory
available. Determine if memory exists by writing to a few
strategic locations and see if the data can be read back. If
so, perform an address-line test and a RAM test on the
memory. Save the total extended LBT Core
0x62 The amount of memory available. This test is dependent
on the processor, since the test will vary depending on the
width of memory (16 or 32 bits). This test will also use A20
as the skew address to prevent corruption of the system
memory. LBT Core
0x64 Jump to UserPatch1. LBT Core
0x66 Set cache registers to their CMOS values if CMOS is valid,
unless auto configuration is enabled, in which case load
cache registers from the Setup default table. LBT Core
0x68 Enable external cache and CPU cache if present.
Configure non-cacheable regions if necessary. LBT Core
0x6A Display external cache size on the screen if it is non-zero. LBT Core
0x6C Display shadow message LBT Core
0xCA Post EISA init LBT Core
0x70 Check flags in CMOS and in the TrustedCore data area for
errors detected during POST. Display error messages on
the screen. LBT Core
0x72 Check status bits to see if configuration problems were
detected. If so, display error messages on the screen. LBT Core
0x4F Initialize MultiBoot. Allocate memory for old and new
MultiBoot history tables. LBT Core
0xCD Reclaim console vector after HW vectors initialized. LBT Core
0x7D Initialize Intelligent System Monitoring. LBT Core
0x7E The Coprocessor initialization test. Use the floating point
instructions to determine if a coprocessor exists instead of
the ET bit in CR0. LBT Core
0xC1 Check Boot Type (Server BIOS) LBT Core
0x80 Disable onboard COM and LPT ports before testing for
presence of external I/O devices. LBT Core
Table 4-4. POST Codes
POST Code Function Phase Component