Chapter 4
103
* If the BIOS detects error 2C, 2E, or 3O (base 512K RAM error), it displays an additional word-bitmap (xxxx) indicating
the address line or bits that failed. For example, "2C 0002" means address line 1 (bit one set) has failed. "2E 1020"
means data bits 12 and 5 (bits 12 and 5 set) have failed in the lower 16 bits. Note that error 30 cannot occur on 386SX
systems because they have a 16 rather than 32-bit bus. The BIOS also sends the bitmap to the port-80 LED display. It
first displays the check point code, followed by a delay, the high-order byte, another delay, and then the low-order byte
of the error. It repeats this sequence continuously.
BIOS Beep Codes for Boot Block in Flash ROM
C4h
Initialize system error handler
C5h
PnPnd dual CMOS (optional)
C6h
Initialize notebook docking (optional)
C7h
Initialize notebook docking late
C8h
Force check (optional)
C9h
Extended checksum (optional)
D2h
Unknown interrupt
Code
Beeps
For Boot Block in Flash ROM
E0h
Initialize the chipset
E1h
Initialize the bridge
E2h
Initialize the CPU
E3h
Initialize the system timer
E4h
Initialize system I/O
E5h
Check force recovery boot
E6h
Checksum BIOS ROM
E7h
Go to BIOS
E8h
Set Huge Segment
E9h
Initialize Multiprocessor
EAh
Initialize OEM special code
EBh
Initialize PIC and DMA
ECh
Initialize Memory type
EDh
Initialize Memory size
EEh
Shadow Boot Block
EFh
System memory test
F0h
Initialize interrupt vectors
F1h
Initialize Run Time Clock
F2h
Initialize video
F3h
Initialize System Management Mode
F4h
1
Output one beep before boot
F5h
Boot to Mini DOS
F6h
Clear Huge Segment
F7h
Boot to Full DOS
Code
Beeps
POST Routine Description
SG_TM4720_4320_Book.book Page 103 Friday, April 20, 2007 11:14 AM
Содержание TravelMate 4720 Series
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Страница 48: ...38 Chapter 1 ...
Страница 76: ...66 Chapter 3 5 Disconnect the keyboard cable from the mainboard to remove the keyboard ...
Страница 91: ...Chapter 3 81 16 Carefully detach the speaker modules as shown ...
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Страница 120: ...110 Chapter 4 ...
Страница 121: ...Chapter 5 111 System Block Diagram System Block Diagram and Connector Locations Chapter 5 ...
Страница 122: ...112 Chapter 5 Board Layout Top and Bottom View ...
Страница 126: ...116 Chapter 5 ...
Страница 128: ...118 Chapter 4 Travelmate 4720 4320 Exploded Diagram ...
Страница 141: ...131 Appendix A ...
Страница 142: ...Appendix A 132 ...
Страница 146: ...136 Appendix C ...