Code |
Beeps |
POST Routine Description |
| 02h |
|
Verify Real
Mode |
| 03h |
|
Disable
Non-Maskable Interrupt (NM) |
| 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 boost |
| 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 |
|
Autosize DRAM |
| 29h |
|
Initialize POST
Memory Manager |
| 2Ah |
|
Clear 512 KB
base RAM |
| 2Ch |
1-3-4-2 |
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 |
| 30th |
1-4-1-1 |
RAM failure on
data bits xxxx*of high byte memory bus |
| 32h |
|
Test CPU
bus-clock frequency |
| 33h |
|
Initialize
Phoenix Dispatch Manager |
| 36h |
|
Warm start shut
down |
| 38h |
|
Shadow system
BIOS ROM |
| 3Ah |
|
Autosize cache |
| 3Ch |
|
Advanced
configuration of chipset registers |
| 3Dh |
|
Load alternate
registers with CMOS values |
| 42h |
|
Initialize
interrupt vectors |
| 45h |
|
POST device
initialization |
| 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 |
|
Display BIOS
copyright notice |
| 50Eh |
|
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
UserPatchI |
| 66h |
|
Configure
advanced cache registers |
| 67h |
|
Initialize
Multi Processor APIC |
| 68h |
|
Enable external
and CPU cache |
| 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 |
|
Reinitialize
onboard I/O ports |
| 87h |
|
Configure
Motherboard Configurable Devices (optional) |
| 88h |
|
Initialize BIOS
Data Area |
| 89h |
|
Enable
Non-Maskable Interrupts (NMIs) |
| 8Ah |
|
Initialize
Extended BIOS Data Area |
| 8Bh |
|
Test and
initialize PS/2 mouse |
| 8Ch |
|
Initialize
floppy controller |
| 81h |
|
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 |
|
Clear huge ES
segment register |
| 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 shot 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
back up 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 |
|
PnPnd dual CMOS
(optional) |
| C6h |
|
Initialize
notebook docking (optional) |
| C7h |
|
Initialize
notebook docking late |
| C8h |
|
Force check
(optional) |
| C9h |
|
Extended
checksum (optional) |
| D2h |
|
Unknown
interrupts |