01 | Disable the NMI and test CPU registers |
02 | Verify the BIOS ROM checksum (32KB at F8000h) |
03 | Initialize the keyboard controller and CMOS RAM communication |
04 | Disable the DMA and PIT; test the CMOS RAM interrupt |
05 | Reset the video controller |
06 | Test the 8254 programmable interrupt timer |
07 | Test delta count timer channel 2 (speaker) |
08 | Test delta count timer channel 1 (memory refresh) |
09 | Test delta count timer channel 0 (system timer) |
0A | Test parity circuit and turn on refresh |
0B | Enable parity check and test system timer |
0C | Test refresh trace link toggle |
0D | Test refresh timing synchronization |
10 | Disable cache and shadow memory; test the 64KB base memory |
11 | Perform 64KB memory read/write test |
12 | Initialize interrupt vector table in lower 1KB of RAM |
14 | Test CMOS RAM shutdown register...disable DMA and interrupt controllers |
15 | Test CMOS RAM battery and checksum |
16 | Test for floppy drive, based on CMOS setup...initialize monochrome video |
17 | Initialize CGA video |
18 | Clear the parity status (if any) |
19 | Test for EGA/VGA video BIOS at C0000h and pass control |
1A | Return from video ROM |
1B | Test primary video adapter...test video memory |
1C | Test secondary video adapter...test video memory |
1D | Compare CMOS settings to video adapter |
1E | Set video mode according to CMOS settings |
20 | Display CMOS RAM read/write errors and halt |
21 | Set cursor and call interrupt 10 to display status message |
22 | Display power on message; "386 BIOS"; check if CPU speed is 25Mhz or 33Mhz |
23 | Read new cursor position |
24 | Display AMI copyright message at the bottom of the screen |
25 | Test shadow RAM |
F0 | Shadow RAM test failed |
30 | Ready to enter protected mode |
31 | Enter protected mode (A20 gate) and enable timer interrupt (IRQ 0) |
32 | Get memory size above 1MB |
33 | Get memory size below 640KB |
34 | Test memory above 1MB |
35 | Test memory below 1MB |
37 | Clear memory below 1MB |
38 | Clear memory above 1MB |
39 | Use CMOS shutdown byte and return to real mode |
3A | Test 64KB read/write |
3B | Test RAM below 1MB and show the area being tested |
3C | Test RAM above 1MB and show the area being tested |
3D | RAM test complete OK |
3E | Ready to return to real mode |
3F | Back in real mode |
40 | Disable A20 gate |
41 | Check for AMI copyright message in ROM |
42 | Display the AMI copyright message, if found |
43 | Test cache memory; Clear <Esc> message |
4E | Process shutdown 1; Return to real mode |
4F | Restore interrupt vectors and data in BIOS RAM area |
50 | Test DMA controller |
51 | Initialize DMA controller |
52 | Test the DMA controller with patterns |
54 | Test DMA controller latches |
55 | Initialize and enable DMA controllers 1 and 2 |
56 | Initialize 8259 programmable interrupt controllers |
57 | Test 8259 programmable interrupt controllers and setup interrupt mask registers |
61 | Check DDNIL status bit and display message |
70 | Perform keyboard (BAT) basic assurance test |
71 | Program keyboard to AT type |
72 | Disable keyboard and initialize keyboard circular buffer |
73 | Display message and initialize floppy controller and drive |
74 | Attempt to access the floppy drive |
75 | If the CMOS RAM is good, check and initialize the hard disk controller and drive |
76 | Attempt to access the hard disk drive |
77 | Shuffle and internal error codes |
79 | Check CMOS RAM battery and checksum...clear parity status |
7A | Compare size of base/extended memory to CMOS information |
7B | Unknown AMI function |
7C | Display AMI copyright |
7D | Set AT memory expansion bit |
7E | Verify the ROM contains and AMI copyright |
7F | Clear the <Del> message from the display...check if <Del> was pressed |
80 | Locate option ROM at C800h to DE00h and pass control to any found |
81 | Return from option ROM and initialize timer and data area |
82 | Setup parallel and serial ports |
83 | Test for math coprocessor |
84 | Check if keyboard is locked |
85 | Display any soft error messages |
86 | Test for option ROM at E0000h |
A0 | Error found in 256KB or 1MB RAM IC in lower 640KB |
A1 | Base 64KB random access and data pattern test (only in 386APR and Presto 386SX BIOS) |
A9 | Initialize on board VGA controller (Presto 386SX BIOS) |
B0 | Error in 256KB RAM IC in 640KB |
B1 | Base 64KB random access and data pattern test (only in Presto 386SX BIOS) |
E0 | Return to real mode and initialize base 64KB RAM (Presto) |
E1 | Initialize 640KB RAM (Presto) |
EF | Configuration memory error - can't find memory |
F0 | Test shadow RAM from 04000h |
00 | Call the interrupt 19 boot loader |