7521Plus / N N/B MAINTENANCE
7. Maintenance Diagnostics
7.2 Error Codes : Following is a list of error codes in sequent display on the PIO debug board.
SYSTEM SOFT BIOS:
CODE | DESCRIPTION |
|
| CODE | DESCRIPTION | |
01h | Start of boot loader sequence. |
|
| 1Dh | Initialize color adapter | |
02h | Initialize chipset. |
|
| 1Eh | Initialize monochrome adapter | |
03h | Memory Sizing. |
|
| 1Fh | Test 8237A page registers | |
04h | Perform conventional RAM(1st 640K) test with crossed- |
|
| 20h | Perform keyboard self test | |
|
| pattern R/W |
|
| 21h | Test & initialize keyboard controller |
05h | Move boot loader to the RAM. |
|
| 22h | Check if CMOS RAM valid | |
06h | Start point of execution of boot loader in RAM. |
|
| 23h | Test battery fail & CMOS | |
07h | Shadow system BIOS. |
|
| 24h | Test the DMA controllers | |
08h | Initialize clock synthesizer |
|
| 25h | Initialize 8237A controller | |
09h | Initialize audio controller. |
|
| 26h | Initialize interrupt vectors table. | |
0Ah | Detect internal ISA MODEM |
|
| 27h | RAM quick sizing | |
0Bh | Proceed with normal boot |
|
| 28h | Protected mode entered safely | |
0Ch | Proceed with crisis boot |
|
| 29h | RAM test completed | |
0Fh | DRAM sizing |
|
| 2Ah | Protected mode exit successful | |
10h | Initial L1,L2 cache, make stack and diagnose CMOS. |
|
| 2Bh | Setup shadow | |
11h | Turn off fast A20 for post. Reset GDT's, 8259s quickly. |
|
| 2Ch | Prepare to initialize video | |
12h | Signal power on reset at COMS. |
|
| 2Dh | Search for monochrome adapter | |
13h | Initialize the chipset, (SDRAM). |
|
| 2Eh | Search for color adapter, VGA initialize. | |
14h | Search for ISA bus VGA adapter |
|
| 2Fh | Signon messages displayed | |
15h | Reset counter/timer 1, exite the RAM. |
|
| 30h | Special init of keyboard ctlr | |
16h | User register config through CMOS |
|
| 31h | Test if keyboard present | |
18h | Dispatch to 1st 64K RAM test |
|
| 32h | Test keyboard interrupt | |
19h | Checksum the ROM |
|
| 33h | Test keyboard command Byte | |
1Ah | Reset PIC's(8259s) |
|
| 34h | Test, blank and count all RAM | |
1Bh | Initialize video adapter(s) |
|
| 35h | Protected mode entered safely (2). | |
1Ch | Initialize video (6845 regs) |
|
| 36h | RAM test complete | |
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