![](/images/new-backgrounds/1266730/266730185x1.webp)
Code | Beeps | POST Routine Description |
|
|
|
3Ch |
| Advanced configuration of chipset |
|
| registers |
|
|
|
3Dh |
| Load alternate registers with CMOS |
|
| values |
|
|
|
42h |
| Initialize interrupt vectors |
|
|
|
45h |
| POST device initialization |
|
|
|
46h | 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 |
|
|
|
50h |
| Display CPU type and speed |
|
|
|
51h |
| Initialize EISA board |
|
|
|
52h |
| Test keyboard |
|
|
|
54h |
| Set key click if enabled |
|
|
|
58h | 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 User Patch1 |
|
|
|
66h |
| Configure advanced cache registers |
|
|
|
67h |
| Initialize Multi Processor APIC |
|
|
|
68h |
| Enable external and CPU caches |
|
|
|
69h |
| Setup System Management Mode (SMM) |
|
| area |
|
|
|
6Ah |
| Display external L2 cache size |
|
|
|
6Bh |
| Load custom defaults (optional) |
|
|
|
6Ch |
| Display |
|
|
|
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 |
|
|
|
Chapter 4 | 85 |