Code |
Beeps | |
02h |
Verify Real Mode | |
03h |
Disable Non-Maskable Interrupt (NMI) | |
04h |
Get CPU type | |
06h |
Initialize system hardware | |
08h |
Initialize chipset with initial POST values | |
09h |
Set IN POST flag | |
0Ah |
Initialize CPU registers | |
0Bh |
Enable CPU cache | |
0Ch |
Initialize caches to initial POST values | |
0Eh |
Initialize I/O component | |
0Fh |
Initialize the local bus IDE | |
10h |
Initialize Power Management | |
11h |
Load alternate registers with initial POST values | |
12h |
Restore CPU control word during warm boot | |
13h |
Initialize PCI Bus Mastering devices | |
14h |
Initialize keyboard controller | |
16h |
1-2-2-3 |
BIOS ROM checksum |
17h |
Initialize cache before memory autosize | |
18h |
8254 timer initialization | |
1Ah |
8237 DMA controller initialization | |
1Ch |
Reset Programmable Interrupt Controller | |
20h |
1-3-1-1 |
Test DRAM refresh |
22h |
1-3-1-3 |
Test 8742 Keyboard Controller |
24h |
Set ES segment register to 4 GB | |
26h |
Enable A20 line | |
28h | ||
29h |
Initialize POST Memory Manager | |
2Ah |
Clear 215 KB base RAM | |
2Ch |
1-3-4-1 |
RAM failure on address line xxxx |
2Eh |
1-3-4-3 |
RAM failure on data bits xxxx of low byte of memory bus |
2Fh |
Enable cache before system BIOS shadow | |
30h |
1-4-1-1 |
RAM failure on data bits xxxx of high byte of memory bus |
32h |
Test CPU bus-clock frequency | |
33h |
Initialize Phoenix Dispatch Manager | |
36h | ||
38h |
Shadow system BIOS ROM | |
3Ah | ||
3Ch |
Advanced configuration of chipset registers | |
3Dh |
Load alternate registers with CMOS values | |
42h | ||
45h |
POST device initialization |
Code |
Beeps |
POST Routine Description |
46h |
2-1-2-3 |
Check ROM copyright notice |
48h |
Check video configuration against CMOS | |
49h |
Initialize PCI bus and devices | |
4Ah |
Initialize all video adapters in system | |
4Bh |
QuietBoot start (optional) | |
4Ch |
Shadow video BIOS ROM | |
4Eh | ||
50h |
Display CPU type and speed | |
51h |
Initialize EISA board | |
52h |
Test keyboard | |
54h |
Set key click if enabled | |
58h |
2-2-3-1 |
Test for unexpected interrupts |
59h |
Initialize POST display service | |
5Ah |
Display prompt "Press F2 to enter SETUP" | |
5Bh |
Disable CPU cache | |
5Ch |
Test RAM between 512 and 640 KB | |
60h |
Test extended memory | |
62h |
Test extended memory address lines | |
64h |
Jump to User Patch1 | |
66h |
Configure advanced cache registers | |
67h |
Initialize Multi Processor APIC | |
68h | ||
69h |
Setup System Management Mode (SMM) area | |
6Ah |
Display external L2 cache size | |
6Bh |
Load custom defaults (optional) | |
6Ch |
Display shadow-area message | |
6Eh |
Display possible high address for UMB recovery | |
70h |
Display error messages | |
72h |
Check for configuration errors | |
76h |
Check for keyboard errors | |
7Ch |
Set up hardware interrupt vectors | |
7Eh |
Initialize coprocessor if present | |
80h |
Disable onboard Super I/O ports and IRQs | |
81h |
Late POST device initialization | |
82h |
Detect and install external RS232 ports | |
83h |
Configure non-MCD IDE controllers | |
84h |
Detect and install external parallel ports | |
85h |
Initialize PC-compatible PnP ISA devices | |
86h |
Re-initialize onboard I/O ports | |
87h |
Configure Motherboard Configurable Devices (optional) | |
88h |
Initialize BIOS Area | |
89h |
Enable Non-Maskable Interrupts (NMIs) | |
8Ah |
Initialize Extended BIOS Data Area | |
8Bh |
Test and initialize PS/2 mouse |
Code |
Beeps |
POST Routine Description |
8Ch |
Initialize floppy controller | |
8Fh |
Determine number of ATA drives (optional) | |
90h |
Initialize hard-disk controllers | |
91h |
Initialize local-bus hard-disk controllers | |
92h |
Jump to UserPatch2 | |
93h |
Build MPTABLE for multi-processor boards | |
95h |
Install CD ROM for boot | |
96h | ||
97h |
Fixup Multi Processor table | |
98h |
1-2 |
Search for option ROMs. One long, two short beeps on checksum failure. |
99h |
Check for SMART drive (optional) | |
9Ah |
Shadow option ROMs | |
9Ch |
Set up Power Management | |
9Dh |
Initialize security engine (optional) | |
9Eh |
Enable hardware interrupts | |
9Fh |
Determine number of ATA and SCSI drives | |
A0h |
Set time of day | |
A2h |
Check key lock | |
A4h |
Initialize Typematic rate | |
A8h |
Erase F2 prompt | |
AAh |
Scan for F2 key stroke | |
ACh |
Enter SETUP | |
AEh |
Clear Boot flag | |
B0h |
Check for errors | |
B2h |
POST done- prepare to boot operating system | |
B4h |
1 |
One short beep before boot |
B5h |
Terminate QuietBoot (optional) | |
B6h |
Check password (optional) | |
B9h |
Prepare Boot | |
BAh |
Initialize DMI parameters | |
BBh |
Initialize PnP Option ROMs | |
BCh |
Clear parity checkers | |
BDh |
Display MultiBoot menu | |
BEh |
Clear screen (optional) | |
BFh |
Check virus and backup reminders | |
C0h |
Try to boot with INT 19 | |
C1h |
Initialize POST Error Manager (PEM) | |
C2h |
Initialize error logging | |
C3h |
Initialize error display function | |
C4h |
Initialize system error handler | |
C5h | ||
C6h |
Initialize notebook docking (optional) | |
C7h |
Initialize notebook docking late | |
C8h |
Force check (optional) | |
C9h |
Extended checksum (optional) |
Code |
Beeps |
POST Routine Description |
D2h |
Unknown interrupt | |
Code |
Beeps | |
E0h | ||
E1h | ||
E2h |
Initialize the CPU | |
E3h | ||
E4h |
Initialize system I/O | |
E5h |
Check force recovery boot | |
E6h |
Checksum BIOS ROM | |
E7h |
Go to BIOS | |
E8h |
Set Huge Segment | |
E9h |
Initialize Multi Processor | |
EAh | ||
EBh |
Initialize PIC and DMA | |
ECh |
Initialize Memory type | |
EDh |
Initialize Memory size | |
EEh | ||
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 | ||
F6h |
Clear Huge Segment | |
F7h |
Boot to Full DOS |
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Read how to maintain and repair any desktop and laptop computer. This Ebook has articles with photos and videos that show detailed step by step pc repair and maintenance procedures. There are many links to online videos that explain how you can build, maintain, speed up, clean, and repair your computer yourself. Put the money that you were going to pay the PC Tech in your own pocket.
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