Presario 1200 series – Compaq XL118-XL127 User Manual
Page 77

P
RESARIO
N
OTEBOOK
M
AINTENANCE
AND
S
ERVICE
G
UIDE
1200XL S
ERIES
T
ROUBLESHOOTING
35
Presario 1200 Series
Models: XL101-XL113, XL115, XL118-XL127
12
h
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
Test DRAM refresh
22h
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
RAM failure on address line xxxx*RAM failure on data
bits xxxx* of low byte of memory bus
2Eh
Enable cache before system BIOS shadow
2Fh
RAM failure on data bits xxxx*of high byte memory bus
30th
Test CPU bus-clock frequency
32h
Initialize Phoenix Dispatch Manager
33h
Warm start shut down
36h
Shadow system BIOS ROM
38h
Autosize cache
3Ah
Advanced configuration of chipset registers
3Ch
Load alternate registers with CMOS values
3Dh
Initialize interrupt vectors
42h
POST device initialization
45h
Check ROM copyright notice
46h
Check Video configuration against CMOS
48h
Initialize PCI bus and devices
Code
Beeps
POST Routine Description