Acer extensa 390 Service Manual
E-2
Service Guide
Table E-1
POST Checkpoint List
Checkpoint
Description
20h
•
KB controller(8041/8042) testing
•
KB type determination
•
Write default command byte upon KB type
24h
•
PIC(8259) testing & initialization
30h
•
System Shadow RAM
34h
•
DRAM sizing
3Ch
•
Initialize interrupt vectors
4Bh
•
Identify CPU brand and type
35h
•
PCI pass 0
40h
•
Assign I/O if device request
41h
•
Assign Memory if device requested
44h
•
Assign IRQ if device request
45h
•
Enable command byte if device is OK
50h
•
Initialize Video display
52h
•
Download keyboard matrix
4Ch
•
ChipUp initialization for CPU clock checking
54h
•
Process VGA shadow region
58h
•
Set POST screen mode(Graphic or Text)
•
Display Acer(or OEM) logo if necessary
•
Display Acer copyright message if necessary
•
Display BIOS serial number
59h
•
Hook int vector 1ch for POST quiet boot
5Ch
•
Memory testing
5Ah
•
SMRAM test and SMI handler initialization
4Eh
•
Audio initialization
60h
•
External Cache sizing
•
External Cache testing(SRAM & Controller)
•
Enable internal cache if necessary
•
Enable external cache if necessary
64h
•
Reset KB device
•
Check KB status
Note: The keyboard LEDs should flash once.
7Ch
•
Reset pointing device
•
Check pointing device
70h
•
Parallel port testing
74h
•
Serial port testing
78h
•
Math Coprocessor testing