The original list from bioscentral.com seems to have gone down as of January 2024, so we’ve recompiled that list down below.
Last updated: 21st Jan 2024
Beep codes
| Beeps | Error Message | Description |
| 1long, 2 short | Video adapter error | Either video adapter is bad or is not seated properly. Also, check to ensure the monitor cable is connected properly. |
| Repeating (endless loop) | Memory error | Check for improperly seated or missing memory. |
| 1long, 3short | No video card or bad video RAM | Reseat or replace the video card. |
| High frequency beeeps while running | Overheated CPU | Check the CPU fan for proper operation. Check the case for proper air flow. |
| Repeating High/Low | CPU | Either the CPU is not seated properly or the CPU is damaged. May also be due to excess heat. Check the CPU fan or BIOS settings for proper fan speed. |
POST codes
Original XT version
| 03 | Flag resister test |
| 06 | CPU register test |
| 09 | System hardware initialization |
| 0C | BIOS checksum |
| 0F | DMA page register initialization |
| 12 | Test DMA address and count registers |
| 15 | DMA initialization |
| 18 | Timer test |
| 1B | Timer initialization |
| 1E | Start RAM initialization |
| 21 | Test base 64K of RAM |
| 24 | Setup init. and temp stack |
| 27 | Initialize PIC |
| 2A | Interrupt mask register test |
| 2D | Hot interrupt test |
| 30 | V40 DMA if present |
| 33 | Verify system clock initialization |
| 36 | Keyboard test |
| 39 | Setup interrupt table |
| 3C | Read system configuration switches |
| 3F | Video test |
| 42 | Serial port determination |
| 45 | Parallel port determination |
| 48 | Game port determination |
| 4B | Copyright message display |
| 4E | Calculation of CPU speed |
| 54 | Test of system memory |
| 55 | Floppy drive test |
| 57 | System initialized before boot |
| 5A | Call to Int 19 |
XT version 3.1
| 01 | Processor test fail; Processor status verification #1 |
| 02 | Type of POST/keyboard buffer; Failed if the keyboard interface buffer is filled with data |
| 06 | Initialize 6845 video controller, 8237 DMA controller, 8259 PIC, 8253 timer channel channel 1 initialized; Reset math coprocessor; Disable color and mono video, parity circuits and DMA chips; Clear DMA chips and page registers |
| 07 | Process registers except SS, SP, BP with data patterns 00 and FF; Processor status verification #2 |
| 09 | ROM checksum for 32K tested |
| 0A | Initialize the 6845 video controller |
| 15 | Test first 64K of system memory |
| 16 | Set up interrupt table in first 64K |
| 17 | Set up video I/O operations |
| 18 | Test video memory |
| 19 | 8259 mask bits-channel 1 |
| 1A | 8259 mask bits-channel 2 |
| 1D | Setup configuration byte from CMOS |
| 1E | Size memory and compare with CMOS |
| 1F | Test base memory; Test found system memory |
| 20 | Test stuck 8259’s Interrupt bits |
| 21 | Test stuck NMI parity I/O bits |
| 22 | 8259 Interrupt functionality tested |
| 2A | Keyboard initialized |
| 2B | Floppy dive controller and drive initialized |
| 2C | Initialize COM ports |
| 2D | Initialize LPT ports |
| 2F | Initialize math coprocessor |
| 31 | Initialize option ROM’s |
| FF | Int. 19 boot attempt |
Version 3.3
| 01-05 | Keyboard controller 8042 tested |
| 06 | On-board LSI initialized |
| 07 | CPU flags tested |
| 08 | Calculate CMOS checksum |
| 09 | Initialize the 8254 PIT |
| 0A | 8254 PIC tested |
| 0B | DMA controller tested |
| 0C | 8259 PIC initialized |
| 0D | 8259 PIC tested |
| 0E | ROM BIOS checksum tested |
| 0F | Extended CMOS tested |
| 10 | 8259 PIC tested |
| 11 | 8259 PIC tested |
| 12 | 8259 PIC tested |
| 13 | 8259 PIC tested |
| 14 | 8259 PIC tested |
| 15 | First 64K RAM tested |
| 16 | Interrupt vector tables initialized |
| 17 | Video initialization |
| 18 | Video memory tested |
| 19 | Interrupt line mask 8259 PIC tested |
| 1A | Interrupt line mask 8259 PIC tested |
| 1B | Battery good |
| 1C | CMOS checksum verified |
| 1D | CMOS chip/RTC verified |
| 1E | Memory size checked |
| 1F | Memory verified |
| 20 | DMA initialized |
| 21 | PIC initialized |
| 22 | PIT initialized |
| 24 | Extended memory size checked |
| 25 | Extended memory tested |
| 26 | Protected mode entered |
| 27 | Shadow RAM, cache controller initialized |
| 28 | Shadow RAM, cache controller tested |
| 29 | Reserved |
| 2A | Initialize keyboard |
| 2B | Floppy drive initialization |
| 2C | Serial port initialization |
| 2D | Parallel port initialization |
| 2E | Hard disk initialization |
| 2F | Math coprocessor |
| 30 | Reserved |
| 31 | Optional ROM’s checked for |
| FF | Boot from Int 19 |
EISA BIOS
| 01 | CPU flags |
| 02 | CPU registers |
| 03 | Initialize DMA, PIC, PIT |
| 04 | Memory refresh |
| 05 | Keyboard initialization |
| 06 | ROM checksum |
| 07 | CMOS, battery |
| 08 | 256K memory |
| 09 | Cache |
| 0A | Set Interrupt table |
| 0B | CMOS checksum |
| 0C | Keyboard initialization |
| 0D | Video adapter |
| 0E | Video memory |
| 0F | DMA channel 0 |
| 10 | DMA channel 1 |
| 11 | DMA page register |
| 14 | Timer chip |
| 15 | PIC controller 1 |
| 16 | PIC controller 0 |
| 17 | PIC stuck bits |
| 18 | PIC maskable IRQ’s |
| 19 | NMI bit check |
| 1F | CMOS XRAM |
| 20 | Slot 0 |
| 21 | Slot 1 |
| 22 | Slot 2 |
| 23 | Slot 3 |
| 24 | Slot 4 |
| 25 | Slot 5 |
| 26 | Slot 6 |
| 27 | Slot 7 |
| 28 | Slot 8 |
| 29 | Slot 9 |
| 2A | Slot 10 |
| 2B | Slot 11 |
| 2C | Slot 12 |
| 2D | Slot 13 |
| 2E | Slot 14 |
| 2F | Slot 15 |
| 30 | Memory size 256K |
| 31 | Memory test over 256K |
| 32 | EISA memory |
| 3C | CMOS setup |
| 3D | Mouse/adapter, CMOS |
| 3E | Cache RAM |
| 3F | Shadow RAM |
| 41 | Floppy drive |
| 42 | Hard drive |
| 43 | RS232 parallel |
| 45 | NPU |
| 47 | Speed |
| 4E | Manufacturing loop |
| 4F | Security |
| 50 | CMOS update |
| 51 | Enable NMI, cache |
| 52 | Adapter ROM’s |
| 53 | Set time |
| 60 | Virus protection setup |
| 61 | Boot speed |
| 62 | Numlock setup |
| 63 | Boot |
| B0 | NMI in protected |
| B1 | Disable NMI |
| BE | Chipset default initialization |
| BF | Chipset program |
| C0 | Cache on/off |
| C1 | Memory size |
| C2 | Base 256K test |
| C3 | DRAM page select |
| C4 | Video switch |
| C5 | Shadow RAM |
| C6 | Cache program |
| C8 | Speed switch |
| C9 | Shadow RAM |
| CA | OEM chipset |
| FF | Boot |
Version 4.0
| 01 | CPU flags tested; Processor test #1 |
| 02 | CPU registers tested; Processor test #2; Verify all CPU registers except SS, SP, BP with data patterns 00 and FF |
| 03 | Initialize DMA, PIC, PIT; Calculate BIOS EPROM and sign on message checksum (fail if not 0) |
| 04 | Memory refresh initialized; Test CMOS RAM interface |
| 05 | Keyboard initialization; Initialize NMI, PIE, AIE, UEI, SQWV; Disable video, parity checking and DMA; Math coprocessor reset; Clear all page registers and CMOS RAM shutdown byte; Initialize timers 0, 1, 2 and set EISA timer to a known state; Initialize DMA controllers 0 and 1; Initialize interrupt controllers 0 and 1; Initialize EISA extended registers |
| 06 | ROM checksum; Memory refresh tested |
| 07 | Low memory setup; Initialize chipset and test the presence of memory; OEM chipset initialization; Lower 256K of memory cleared; Enable parity checking and test parity in lower 256K memory |
| 08 | Setup Interrupt vector table; Initialize the first 120 Interrupt vectors with SPURIOUS_INT_HDLR and initialize INT 00-1F according to INT_TBL |
| 09 | Cache; CMOS checksum tested |
| 0A | Set interrupt table; Initialize keyboard; Detect keyboard controller |
| 0B | CMOS checksum; Video interface initialized |
| 0C | Keyboard initialization; Video memory tested |
| 0D | Video adapter initialized; OEM specific initializations |
| 0E | Reserved |
| 0F | DMA channel 0 tested with AA, 55, FF, 00 bit patterns |
| 10 | DMA channel 1 tested with AA, 55, FF, 00 bit patterns |
| 11 | DMA page register tested |
| 12 | Reserved |
| 13 | Reserved |
| 14 | Timer chip 8254 PIT timer 0 counter 2 tested |
| 15 | Verify 8259 PIC channel 1 |
| 16 | Verify 8259 PIC channel 2 |
| 17 | 8259 PIC stuck bits tested; Turn Interrupt bits off and verify no Interrupt mask register is on |
| 18 | 8259 PIC maskable IRQ’s tested |
| 19 | NMI bit check tested and parity I/O checked |
| 1A | Reserved |
| 1B | Reserved |
| 1C | Reserved |
| 1D | Reserved |
| 1E | Reserved |
| 1F | CMOS XRAM checked for |
| 20 | Slot 0 EISA initialized and enabled |
| 21 | Slot 1 EISA initialized and enabled |
| 22 | Slot 2 EISA initialized and enabled |
| 23 | Slot 3 EISA initialized and enabled |
| 24 | Slot 4 EISA initialized and enabled |
| 25 | Slot 5 EISA initialized and enabled |
| 26 | Slot 6 EISA initialized and enabled |
| 27 | Slot 7 EISA initialized and enabled |
| 28 | Slot 8 EISA initialized and enabled |
| 29 | Slot 9 EISA initialized and enabled |
| 2A | Slot 10 EISA initialized and enabled |
| 2B | Slot 11 EISA initialized and enabled |
| 2C | Slot 12 EISA initialized and enabled |
| 2D | Slot 13 EISA initialized and enabled |
| 2E | Slot 14 EISA initialized and enabled |
| 2F | Slot 15 EISA initialized and enabled |
| 30 | Memory size below 256K |
| 31 | Memory test over 256K |
| 32 | EISA memory tested found during slot initialization |
| 3C | CMOS setup; Enter protected mode |
| 3D | Mouse/adapter, CMOS |
| 3E | Cache RAM |
| 3F | Shadow RAM |
| 41 | Initialize floppy drive |
| 42 | Initialize hard drive |
| 43 | RS232 parallel |
| 45 | NPU |
| 47 | Speed for boot set |
| 4E | Manufacturing loop; display any soft errors |
| 4F | Security; ask for password if security is enabled |
| 50 | CMOS update |
| 51 | Enable NMI, cache memory |
| 52 | Adapter ROM’s from C8000h to EFFFFH or F7FFFh initialized |
| 53 | Set time value for address 40 of BIOS |
| 60 | Virus protection setup |
| 61 | Boot speed |
| 62 | Numlock setup |
| 63 | Boot from Int 19 |
| B0 | NMI in protected |
| B1 | Disable NMI |
| BE | Chipset default initialization |
| BF | Chipset program; initialization of system specific chipsets |
| C0 | Cache on/off |
| C1 | Memory size checked |
| C2 | Base 256K tested |
| C3 | DRAM page select tested |
| C4 | Video switch |
| C5 | Shadow RAM tested |
| C6 | Cache program; configure cache memory |
| C8 | Speed switch |
| C9 | Shadow RAM tested |
| CA | OEM chipset initialized |
| FF | Boot from Int 19 |
Award PnP
| 01 | Reserved |
| 02 | Reserved |
| 03 | Initialize EISA registers (EISA BIOS only) |
| 04 | Reserved |
| 05 | Keyboard controller self-tested |
| 06 | Reserved |
| 07 | Verify CMOS Read/Write |
| 09 | OEM specific initialization; Configure Cyrix CPU register |
| 0A | Issue CPU ID instruction; Initialize the first 32 interrupt vectors, initialize Int.’s 33 to 120, power management initialization |
| 0B | PnP initialization; verify the RTC time, detect bad battery, read the CMOS data into the BIOS stack area, assign I/O and memory for any PCI devices |
| 0C | Initialization of BIOS data area |
| 0D | Program some of chipset’s value; Measure the CPU for display, initialize the video |
| 0E | Initialize APIC (multiprocessor BIOS only); Show startup screen message |
| 0F | DMA channel 0 tested |
| 10 | DMA channel 1 tested |
| 11 | DMA page registers tested |
| 12 | Reserved |
| 13 | Reserved |
| 14 | Test 8254 0 counter 2 |
| 15 | Test 8259 interrupt mask bit for channel 1 |
| 16 | Test 8259 interrupt mask bit for channel 2 |
| 17 | Reserved |
| 19 | Test 8259 functionality |
| 1A | Reserved |
| 1B | Reserved |
| 1C | Reserved |
| 1D | Reserved |
| 1E | If an EISA NVM |
| 1F-29 | Reserved |
| 30 | Get size of base and extended memory |
| 31 | Test base and extended memory, Test base memory from 256K to 640K , test extended memory above 1MB |
| 32 | Test all on-board super I/O ports |
| 33 | Reserved |
| 3A | Reserved |
| 3B | Reserved |
| 3C | Set flag to allow CMOS setup utility |
| 3D | Install PS/2 mouse |
| 3E | Try to turn on level 2 |
| 3F | Reserved |
| 40 | Reserved |
| 41 | Initialize floppy drive controller |
| 42 | Initialize hard drive controller |
| 43 | Initialize serial & parallel ports (PnP BIOS only) |
| 45 | Initialize math coprocessor |
| 46-4D | Reserved |
| 4E | Show all error messages on screen |
| 4F | Ask for password, if needed |
| 50 | Write all CMOS values located in the BIOS stack back to CMOS |
| 51 | Reserved |
| 52 | Initialize all ISA ROM’s; PCI initializations (PCI BIOS only), PnP initialization (PnP BIOS Only), setup shadow RAM, initialize power management |
| 53 | If not PnP BIOS, initialize ports; Initialize time in BIOS data area |
| 54-5F | Reserved |
| 60 | Setup virus protection for the boot sector |
| 61 | Try to turn on level 2 cache |
| 62 | program numlock & typematic speed |
| 63 | Boot system via Int 19h |
| B0 | Unexpected interrupt in protected mode |
| B1 | Unclaimed NMI occurred |
| BE | Program defaults into chipset |
| BF | Program remaining chipset values |
| C0 | Init. all standard devices with defaults |
| C1 | Auto detect on-board DRAM & cache |
| C3 | Test first 26K DRAM |
| C5 | Copy ROM BIOS to E000-FFFF |
| FF | System booting |
Version 4.51PG
| 01 | Processor test; Processor status verification |
| 02 | Processor test 2; Read/Write and verify all CPU registers |
| 03 | Initialize chips; Disable NMI, PIE, AIE, UEI, SQWV. Disable video, parity checking, DMA. Reset math coprocessor. Clear all page registers and CMOS shutdown. Initialize DMA controller 0 and 1. Initialize interrupt controllers 0 and 1. |
| 04 | Test memory refresh toggle |
| 05 | Blank video, initialize keyboard; Keyboard controller initialization |
| 07 | Test CMOS interface and battery |
| 08 | Set up low memory; Early chipset initialization, memory presence test, OEM chipset routines, clear low 64K memory, test first 64K memory |
| 09 | Early cache initialization; Cyrix CPU specific, CPU and cache initialization |
| 0A | Set up interrupt vector table; Initialize first 120 interrupt vectors |
| 0B | Test CMOS RAM checksum |
| 0C | Initialize keyboard; Detect the type of keyboard controller |
| 0D | Initialize video interface; Detect CPU clock, read CMOS location 14h to find the type of video in use, detect and initialize video adapter |
| 0E | Test video memory; Write sign-on message to screen, setup shadow RAM |
| 0F | Test DMA controller 0; BIOS checksum test, keyboard detect and initialization |
| 10 | Test DMA controller 1 |
| 11 | Test DMA page registers |
| 12-13 | Reserved |
| 14 | Test timer counter 2 |
| 15 | Test 8259-1 mask bits |
| 16 | Test 8259-2 mask bits |
| 17 | Test stuck 8259 interrupt bits; Test stuck key |
| 18 | Test 8259 interrupt functionality |
| 19 | Test stuck NMI bits (parity I/O check) |
| 1A | Benchmark; Display CPU clock |
| 1B-1E | Reserved |
| 1F | Set EISA mode; If the EISA memory checksum is good then EISA is initialized. If it’s not good then ISA tests and clear EISA mode flag |
| 20 | Enable slot 0; System board |
| 21-2F | Enable slots 1-15 |
| 30 | Size base and extended memory; Size the base memory from 256K to 640K and the extended memory above 1MB |
| 31 | Test base and extended memory; Test the base memory from 256K to 640K and the extended memory above 1MB using various bit patterns |
| 32 | Test EISA extended memory |
| 33-3B | Reserved |
| 3C | Setup enabled |
| 3D | Initialize and install mouse if present |
| 3E | Setup cache controller |
| 40 | Display virus protect disable or enable |
| 41 | Initialize floppy |
| 42 | Initialize hard drive |
| 43 | Detect & Init. serial & parallel ports |
| 44 | Reserved |
| 45 | Detect and Init. math coprocessor |
| 46 | Reserved |
| 47 | Reserved |
| 48-4D | Reserved |
| 4E | Mfg. POST loop, or display messages |
| 4F | Security password |
| 50 | Write CMOS; Write CMOS back to RAM and clear screen |
| 51 | Pre-boot enable; Enable parity checking, enable NMI, enable cache before boot |
| 52 | Initialize option ROM’s; Initialize and ROM’s present at locations C800h to EFFFFh |
| 53 | Initialize time value |
| 60 | Setup virus protect |
| 61 | Set boot speed |
| 62 | Setup numlock |
| 63 | Boot attempt |
| B0 | Spurious |
| B1 | Unclaimed NMI |
| BE | Chipset default initialization; Program chipset registers and power-on BIOS defaults. |
| BF | Chipset initialization; Reserved |
| C0 | Turn off chipset cache |
| C1 | Memory presence test; OEM specific, test the size of on-board memory |
| C5 | Early shadow; OEM specific, early shadow enable for fast boot |
| C6 | Cache presence test; External cache-size detection test |
| E1-EF | Setup pages |
| FF | Boot loader |
Version 6.00PG
| CFh | Test CMOS read/write functionality |
| C0h | Early chipset initialization: Disable shadow RAM, L2 cache (socket 7 and below), program basic chipset registers |
| C1h | Detect memory: Auto detection of DRAM size, type and ECC, auto detection of L2 cache (socket 7 and below) |
| C3h | Expand compressed BIOS code to DRAM |
| C5h | Call chipset hook to copy BIOS back to E000 & F000 shadow RAM |
| 01h | Expand the Xgroup codes located in physical memory address 1000:0 |
| 02h | Reserved |
| 03h | Initial Superio_Early_Init switch |
| 04h | Reserved |
| 05h | Blank out screen; Clear CMOS error flag |
| 06h | Reserved |
| 07h | Clear 8042 interface; Initialize 8042 self test |
| 08h | Test special keyboard controller for Winbond 977 series Super I/O chips; Enable keyboard interface |
| 09h | Reserved |
| 0Ah | Disable PS/2 mouse interface (optional); Auto detect ports for keyboard & mouse followed by a port & interface swap (optional); Reset keyboard for Winbond 977 series Super I/O chips |
| 0Bh | Reserved |
| 0Ch | Reserved |
| 0Dh | Reserved |
| 0Eh | Test F000h segment shadow to see whether it is read/write capable or not. If test fails, keep beeping the speaker |
| 0Fh | Reserved |
| 10h | Auto detect flash type to load appropriate flash read/write codes into the run time area in F000 for ESCD & DMI support |
| 11h | Reserved |
| 12h | Use walking 1’s algorithm to check out interface in CMOS circuitry. Also set real time clock power status and then check for overrride |
| 13h | Reserved |
| 14h | Program chipset default values into chipset. Chipset default values are MODBINable by OEM customers |
| 15h | Reserved |
| 16h | Initial Early_Init_Onboard_Generator switch |
| 17h | Reserved |
| 18h | Detect CPU information including brand, SMI type (Cyrix or Intel) and CPU level (586 or 686) |
| 19h | Reserved |
| 1Ah | Reserved |
| 1Bh | Initial interrupts vector table. If no special specified, all H/W interrupts are directed to SPURIOUS_INT_HDLR & S/W interrupts to SPURIOUS_soft_HDLR |
| 1Ch | Reserved |
| 1Dh | Initial EARLY_PM_INIT switch |
| 1Eh | Reserved |
| 1Fh | Load keyboard matrix (notebook platform) |
| 20h | Reserved |
| 21h | HPM initialization (notebook platform) |
| 22h | Reserved |
| 23h | Check validity of RTC value; Load CMOS settings into BIOS stack. If CMOS checksum fails, use default value instead; Prepare BIOS resource map for PCI & PnP use. If ESCD is valid, take into consideration of the ESCD’s legacy information; Onboard clock generator initialization. Disable respective clock resource to empty PCI & DIMM slots; Early PCI initialization – Enumerate PCI bus number, assign memory & I/O resource, search for a valid VGA device & VGA BIOS, and put it into C000:0 |
| 24h | Reserved |
| 25h | Reserved |
| 26h | Reserved |
| 27h | Initialize INT 09 buffer |
| 28h | Reserved |
| 29h | Program CPU internal MTRR (P6 & PII) for 0-640K memory address; Initialize the APIC for Pentium class CPU; Program early chipset according to CMOS setup; Measure CPU speed; Invoke video BIOS |
| 2Ah | Reserved |
| 2Bh | Reserved |
| 2Ch | Reserved |
| 2Dh | Initialize multilanguage; Put information on screen display, including Award title, CPU type, CPU speed, etc… |
| 2Eh | Reserved |
| 2Fh | Reserved |
| 30h | Reserved |
| 31h | Reserved |
| 32h | Reserved |
| 33h | Reset keyboard except Winbond 977 series Super I/O chips |
| 34h | Reserved |
| 35h | Reserved |
| 36h | Reserved |
| 37h | Reserved |
| 38h | Reserved |
| 39h | Reserved |
| 3Ah | Reserved |
| 3Bh | Reserved |
| 3Ch | Test 8254 |
| 3Dh | Reserved |
| 3Eh | Test 8259 interrupt mask bits for channel 1 |
| 3Fh | Reserved |
| 40h | Test 9259 interrupt mask bits for channel 2 |
| 41h | Reserved |
| 42h | Reserved |
| 43h | Test 8259 functionality |
| 44h | Reserved |
| 45h | Reserved |
| 46h | Reserved |
| 47h | Initialize EISA slot |
| 48h | Reserved |
| 49h | Calculate total memory by testing the last double last word of each 64K page; Program writes allocation for AMD K5 CPU |
| 4Ah | Reserved |
| 4Bh | Reserved |
| 4Ch | Reserved |
| 4Dh | Reserved |
| 4Eh | Program MTRR of M1 CPU; initialize L2 cache for P6 class CPU & program cacheable range; Initialize the APIC for P6 class CPU; On MP platform, adjust the cacheable range to smaller one in case the cacheable ranges between each CPU are not identical |
| 4Fh | reserved |
| 50h | Initialize USB |
| 51h | Reserved |
| 52h | Test all memory (clear all extended memory to 0) |
| 53h | Reserved |
| 54h | Reserved |
| 55h | Display number of processors (multi-processor platform) |
| 56h | Reserved |
| 57h | Display PnP logo; Early ISA PnP initialization and assign CSN to every ISA PnP device |
| 58h | Reserved |
| 59h | Initialize the combined Trend Anti-Virus code |
| 5Ah | Reserved |
| 5Bh | Show message for entering AWDFLASH.EXE from FDD (optional feature) |
| 5Ch | Reserved |
| 5Dh | Initialize Init_Onboard_Super_IO switch; Initialize Init_Onboard_AUDIO switch |
| 5Eh | Reserved |
| 5Fh | Reserved |
| 60h | Okay to enter Setup utility |
| 61h | Reserved |
| 62h | Reserved |
| 63h | Reserved |
| 64h | Reserved |
| 65h | Initialize PS/2 mouse |
| 66h | Reserved |
| 67h | Prepare memory size information for function call: INT 15h ax=E820h |
| 68h | Reserved |
| 69h | Turn on L2 cache |
| 6Ah | Reserved |
| 6Bh | Program chipset registers according to items described in Setup & Auto-Configuration table |
| 6Ch | Reserved |
| 6Dh | Assign resources to all ISA PnP devices; Auto assign ports to onboard COM ports if the corresponding item in Setup is set to “AUTO” |
| 6Eh | Reserved |
| 6Fh | Initialize floppy controller; Setup floppy related fields in 40:hardware |
| 70h | Reserved |
| 71h | Reserved |
| 72h | Reserved |
| 73h | Enter AWDFLASH.EXE if: AWDFLASH.EXE is found in floppy dive and ALT+F2 is pressed |
| 74h | Reserved |
| 75h | Detect and install all IDE devices: HDD, LS120, ZIP, CDROM… |
| 76h | Reserved |
| 77h | Detect serial ports and parallel ports |
| 78h | Reserved |
| 79h | Reserved |
| 7Ah | Detect and install coprocessor |
| 7Bh | Reserved |
| 7Ch | Reserved |
| 7Dh | Reserved |
| 7Eh | Reserved |
| 7Fh | Switch back to text mode if full screen logo is supported: if errors occur, report errors & wait for keys, if no errors occur or F1 key is pressed continue – Clear EPA or customization logo |
| 80h | Reserved |
| 81h | Reserved |
| 82H | Call chipset power management hook: Recover the text fond used by EPA logo (not for full screen logo), If password is set, ask for password |
| 83H | Save all data in stack back to CMOS |
| 84h | Initialize ISA PnP boot devices |
| 85h | Final USB initialization; NET PC: Build SYSID structure; Switch screen back to text mode; Set up ACPI table at top of memory; Invoke ISA adapter ROM’s; Assign IRQ’s to PCI devices; Initialize APM; Clear noise of IRQ’s |
| 86h | Reserved |
| 87h | Reserved |
| 88h | Reserved |
| 89h | Reserved |
| 90h | Reserved |
| 91h | Reserved |
| 92h | Reserved |
| 93h | Read HDD boot sector information for Trend Anti-Virus code |
| 94h | Enable L2 cache; Program boot up speed; Chipset final initialization; Power management final initialization; Clear screen and display summary table; Program K^ write allocation; Program P6 class write combining |
| 95h | Program daylight saving; Update keyboard LED and typematic rate |
| 96h | Build MP table; Build and update ESCD; Set CMOS century to 20h or 19h; Load CMOS time into DOS timer tick; Build MSIRQ routing table |
| FFh | Boot attempt (INT 19h) |
Test sequence for versions <= 4.2
| CPU | BIOS sets, verifies and resets the error flags in the CPU. Failure here is normally due to the CPU or system clock |
| POST Determination | BIOS determines whether the motherboard is set for normal operation or a continuous loop of POST. If the POST test is cycled 1-5 times over and over either the jumper for this function is set to burn=in or the circuitry involved has failed |
| Keyboard Controller | BIOS tests the internal operations of the keyboard controller chip (8042). Failure here is normally due to the keyboard chip |
| Burn In Status | 1-5 will repeat if the motherboard is set to burn in. If you haven’t set the motherboard for burn-in mode, there is a short in the circuitry |
| Initialize Chipset | BIOS clears all DMA registers and CMOS status bytes 0E and 0F. BIOS then initializes 8254 timer, Failure of this test is probably due to the timer chip |
| CPU | A bit-pattern is used to verify the functioning of the CPU registers. Failure here is normally down to the CPU or clock chip |
| RTC | BIOS verifies that the real time clock is updating CMOS at normal intervals. Failure is normally the CMOS/RTC or the battery |
| ROM BIOS Checksum | BIOS performs a checksum of itself against a predetermined value that will equal 00. Failure is down to the ROM BIOS |
| Initialize Video | BIOS tests and initializes the video controller. Failure is normally the video controller (6845) or an improper setting of the motherboard or CMOS |
| PIT | BIOS tests the functionality of channels 0, 1, and 2 in sequence. Failure is normally the PIT chip (8254/53) |
| CMOS Status | Walking bit pattern tests CMOS shutdown status byte 0F. Failure normally in CMOS |
| Extended CMOS | BIOS checks for any extended information of the chipset and stores it in the extended RAM area. Failure is normally due to invalid information and can be corrected by setting CMOS defaults. Further failure indicates either the chipset or the CMOS RAM |
| DMA | Channels 0 and 1 are tested together with the page registers of the DMA controller chip (8237). Failure is normally due to the DMA chips |
| Keyboard | The 8042 keyboard controller is tested for functionality and for proper interfacing functions. Failure is normally due to the 8042 chip |
| Refresh | Memory refresh is tested; the standard with walking – bit patterns. Failure is normally the PIT chip in AT’s or the DMA chip in AT’s |
| Memory | The first 64K of memory is tested with walking bit patterns. Failure is normally due to the first bank of ram or a data line |
| Interrupt Vectors | The BIOS interrupt vectors table is loaded to the first bank of RAM. Failure here is not likely since memory in the area has been tested. If failure does occur suspect the BIOS or RTC |
| Video ROM | Video ROM is initialized which performs an internal diagnostic before returning control to the system BIOS. Failure is normally the video adapter or the BIOS |
| Video Memory | This is tested with a bit pattern. This is bypassed if there is a ROM on the video adapter. Failure is normally down to the memory on the adapter |
| PIC | The functionality of the interrupt controller chip(s) is tested (8259). Failure is normally due to the 8259 chips but may be the clock |
| CMOS Battery | BIOS verifies that CMOS byte 0D is set which indicates the CMOS battery power. Suspect the battery first and the CMOS second |
| CMOS Checksum | A checksum is performed on the CMOS. Failure is either incorrect setup, the CMOS chip or battery. If the test is passed, the information is used to configure the system |
| Determine System Memory | Memory up to 640K is addressed in 64K blocks. Failure is normally due to an address line or DMA chip. If all the memory is not found there is a bad RAM chip or address line in the 64K block above the amount found |
| Memory Test | Tests are performed on any memory found and there will normally be a message with the hex address of any failing bit displayed at the end of boot |
| PIC | Further testing is done on the 8259 chips |
| CPU Protected Mode | The processor is placed in protected mode and back into real mode; the 8042 is used for this. In case of failure suspect the 8042, CPU, CMOS, or the BIOS in that order |
| Determine Extended Memory | Memory above 1MB is addressed in 64K blocks. The entire block will be inactive if there is a bad RAM chip on a block |
| Test Extended Memory | Extended memory is tested with a series of patterns. Failure is normally down to a RAM chip, and the hex address of the failed bit should be displayed |
| Unexpected Exceptions | BIOS checks for unexpected exceptions in protected mode. Failure is likely to be a TSR or intermittent RAM failure |
| Shadow Cache | Shadow RAM and cache are activated. Failure may be due to the cache controller or chips. Check the CMOS first for invalid information |
| 8242 Detection | BIOS checks for an Intel 8242 keyboard controller and initializes it if found. Failure may be due to an improper jumper setting or the 8242 |
| Initialize Keyboard | Failure could be the keyboard or controller |
| Initialize floppy | All those set in the CMOS. Failure could be incorrect CMOS setup or floppy controller or the drive |
| Detect Serial Ports | BIOS searches for and initializes up to four serial ports at 3F8, 2F8, 3E8, and 2E8. Detection failure is normally due to an incorrect jumper setting somewhere or an adapter failure |
| Detect Parallel Ports | BIOS searches for and initializes up to four parallel ports at 378, 278, 3BC, and 2BC. Detection failure is normally due to an incorrect jumper setting somewhere or an adapter failure |
| Initialize Hard Drive | BIOS initializes any hard drive(s) set in the CMOS. Failure could be due to invalid CMOS setup, hard drive or controller failure |
| Detect NPU Coprocessor | Initialization of any NPU coprocessor found. failure is due either to invalid CMOS setup or the NPU is failing |
| Initialize Adapter ROM | Any Adapter ROM’s between C800 and EFFF are initialized. The ROM will do an internal test before giving back control to the system ROM. Failure is normally due to the adapter ROM or the attached hardware |
| Initialize External Cache | Any external cache to the 486 is enabled. Failure would indicates invalid CMOS setup, cache controller or chip failure |
| NMI Unexpected Exceptions | A final check for unexpected exceptions before giving control to the Int 19 boot loader. Failure is normally due to a memory parity error or an adapter failure |
| Boot Errors | Failure when the BIOS attempts to boot off the default drive set in CMOS is normally due to invalid CMOS drive setup or as given by an error message. If the system hangs there is an error in the Master Boot Record or the Volume Boot Record |
Test sequence for versions > 4.2
| CPU | BIOS sets, verifies and resets the error flags in the CPU then performs a register test by writing and reading bit patterns. Failure is normally due to the CPU or clock chip |
| Initialize Support Chips | Video is disabled as is parity, DMA and NMI. Then the PIT, PIC, and DMA chips are initialized. Failure is normally the DMA or PIT chips |
| Initialize Keyboard | Keyboard and controller are initialized |
| ROM BIOS Test | A checksum is performed by the ROM BIOS on the data within itself and is compared to a preset value of 00. Failure is normally due tot he ROM BIOS |
| CMOS Test | A test of the CMOS chip which should also detect a bad battery. Failure is due to either the CMOS chip or the battery |
| Memory Test | First 356K of memory tested with any routines in the chipsets. Failure is normally due to defective memory |
| Cache Initialization | Any external cache to the chipset in activated. Failure is normally due to the cache controller or chips |
| Initialize Vector Table | Interrupt vectors are initialized and the interrupt table is installed into low memory. Failure is normally due to the BIOS or low memory |
| CMOS RAM | CMOS RAM checksum tested and BIOS defaults loaded if invalid. Failure would indicate CMOS RAM failure |
| Keyboard Initialization | Keyboard initialized and Num Lock set on. Check the keyboard or controller is a failure occurs |
| Video Test | Video adapter tested and initialized |
| Video Memory | Tested for Mono and CGA adapters. Failure could be the adapter card |
| DMA Test | DMA controllers and page registers are tested. Failure could indicate bad DMA chips |
| PIC Tests | 8259 PIC chips are tested. Failure would indicate a bad PIC |
| EISA Mode Test | A checksum is performed on the extended data area of CMOS where EISA information is stored. If passed the EISA adapter is initialized |
| Enable Slots | Slots 0-15 doe EISA adapters are enabled if the above test is passed |
| Memory Size | Memory addresses above 256K written in 64K blocks and addresses found are initialized. If a bit is bad, the entire block containing it and those above will not be seen |
| Memory Test | Read and write tests are performed on memory above 256K. Failure is due to bad bit in RAM |
| EISA Memory | Memory tests on any adapters initialize previously. Check the memory chips if a failure occurs |
| Mouse Initialization | Checks for a mouse and installs the appropriate interrupt vectors if one is found. Check the mouse adapter if a failure occurs |
| Cache Initialized | The cache controller is initialized if present |
| Shadow RAM Setup | Any Shadow RAM present according to the CMOS is enabled |
| Floppy Test | Test and initialize floppy controller and drive |
| Hard Drive Test | Test and initialize hard disk controller and drive. You may have an improper setup or a bad controller/hard drive if a failure occurs |
| Serial and Parallel Ports | Amy serial and parallel ports are found and initialized |
| Math Coprocessor | The coprocessor is initialized if found. Check the CMOS setup or the math coprocessor if a failure occurs |
| Boot Speed | Set the default speed at which the computer boots |
| POST Loop | Reboot occurs if the loop pin is set for manufacturing purposes |
| Security | Ask for a password if one has been set in the CMOS. |
| Write CMOS | The BIOS is waiting to write the CMOS values from Setup to CMOS RAM. Failure is normally due to an invalid CMOS configuration |
| Pre-Boot | The BIOS is waiting to to write the CMOS values from Setup to CMOS RAM |
| Adapter ROM Initialization | Adapter ROM’s between C800 and EFFF are Initialized. The ROM will do an internal test before giving back control to the system ROM. Failure is normally due to the adapter ROM or the adapter card |
| Setup Time | Set CMOS time to the value located at 40h of the BIOS data area |
| Boot System | Control is given to Int 19 boot loader |
Text error messages
| BIOS ROM checksum error – System halted | The checksum of the BIOS code in the BIOS chip is incorrect, indicating the BIOS code may have become corrupt. Replace the BIOS |
| CMOS battery failed | CMOS battery is no longer functional. Replace the battery |
| CMOS checksum error – Defaults loaded | Checksum of CMOS is incorrect, so the system loads the default values. A checksum error may indicate that CMOS has become corrupt. This error might have been caused by a weak battery |
| CMOS CHECKSUM ERROR DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER | Checksum of CMOS is incorrect. This can indicate that CMOS has become corrupt. This error may have been caused by a weak CMOS battery |
| CPU at nnn | Displays the running speed of the CPU |
| DISKETTE DRIVES OR TYPES MISMATCH ERROR – RUN SETUP | Type of diskette drive installed in the system is different from the CMOS definition. Run Setup to reconfigure the drive type correctly |
| Display switch is set incorrectly | The display switch on the motherboard can be set to either monochrome or color. This message indicates the switch is set to a different setting than indicated in Setup. Determine which setting is correct and then either turn off the system and change the jumper or enter Setup and change the video selector |
| DISPLAY TYPE HAS CHANGED SINCE LAST BOOT | Since last powering off the system, the display adapter has been changed. You must configure the system for the new display type |
| EISA Configuration Checksum Error | The EISA nonvolatile RAM checksum is incorrect or cannot correctly read the EISA slot. This can indicate either the EISA nonvolatile memory has become corrupted or the slot has been configured incorrectly. Also, be sure the card in installed firmly in the slot |
| EISA Configuration Is Not Complete | The slot configuration information stored in the EISA nonvolatile memory is incomplete |
| ERROR ENCOUNTERED INITIALIZING HARD DRIVE | Hard drive cannot be initialized. Be sure the adapter is installed correctly and all cables are correctly and firmly attached. Also be sure the correct hard drive type is selected in Setup |
| ERROR INITIALIZING HARD DISK CONTROLLER | Cannot initialize controller. Make sure the card is correctly and firmly installed in the bus. Be sure the correct hard drive type is installed in Setup. Also check to see if any jumper needs to be set correctly on the hard drive |
| FLOPPY DISK CONTROLLER ERROR OR NO CONTROLLER PRESENT | Cannot find or initialize the floppy disk controller. make sure the controller is installed correctly and firmly. If there are no floppy drives installed, be sure the Diskette Drive selection in Setup is set to None |
| Floppy disk(s) fail | Cannot find or initialize the floppy drive controller or the drive. make sure the controller is installed correctly. If no floppy drives are installed, be sure the Diskette Drive selection in Setup is set to None or Auto |
| HARD DISK initializing | Please wait for a moment… Some hard drives require some extra time to initialize |
| HARD DISK INSTALL FAILURE | Cannot find or initialize the hard drive controller or the drive. Make sure the controller is installed correctly. If no hard drives are installed, be sure the Hard Drive selection in Setup is set to None |
| Hard disk(s) diagnosis fail | The system may run specific disk diagnostic routines. this message appears if one or more hard disks return an error when the diagnostics run |
| Invalid EISA Configuration | The nonvolatile memory containing EISA configuration information was programmed incorrectly or has become corrupt. Rerun EISA configuration utility to correctly program the memory |
| Keyboard error or no keyboard present | Cannot initialize the keyboard. Make sure the keyboard is attached correctly and no keys are being pressed during the boot. If you are purposely configuring the system without a keyboard, set the error halt condition in Setup to HALT ON ALL, BUT KEYBOARD. This will cause the BIOS to ignore the missing keyboard and continue the boot |
| Keyboard is locked out – Unlock the key | This message usually indicates that one or more keys have been pressed during the keyboard tests. Be sure no objects are resting on the keyboard |
| Memory Address Error at… | Indicates a memory address error at a specific location. You can use this location along with the memory map for your system to find and replace the bad memory chips |
| Memory parity Error at… | Indicates a memory parity error at a specific location. You can use this location along with the memory map for your system to find and replace the bad memory chips. |
| MEMORY SIZE HAS CHANGED SINCE LAST BOOT | Memory has been added or removed since the last boot. In EISA mode, use configuration utility to reconfigure the memory configuration. In ISA mode,enter Setup and enter the new memory size in the memory field |
| Memory Test | The message displays during a full memory test, counting down the memory areas being tested |
| Memory Test Fail | If POST detects an error during memory testing, additional information appears giving specifics about the type and location of the memory error |
| Memory Verify Error at… | Indicates an error verifying a value already written to memory. Use the location along with your system’s memory map to locate the bad chip |
| No boot device was found | This could mean that either a boot device was not detected or the drive does not contain proper system boot files. Insert a system disk into drive A: and press Enter. If you assumed the system would boot from the hard drive, make sure the controller is inserted correctly and all cables are properly attached. Also be sure the disk is formatted as a boot device. Then reboot the system |
| OFFENDING ADDRESS NOT FOUND | The message is used in conjunction with the I/O CHANNEL CHECK and RAM PARITY ERROR messages when the segment that has caused the problem cannot be isolated |
| OFFENDING SEGMENT: | This message is used in conjunction with the I/O CHANNEL CHECK and RAM PARITY ERROR messages when the segment that has caused the problem has been isolated |
| Override enabled – Defaults loaded | If the system cannot boot using the current CMOS configuration, the BIOS can override the current configuration with a set of BIOS defaults designed for the most stable, minimal-performance system operations |
| PRESS A KEY TO REBOOT | This will be displayed at the bottom of the screen when an error occurs that requires you to reboot. Press any key to reboot the system |
| Press ESC to skip memory test | You can press ESC to skip the full memory test |
| PRESS F1 TO DISABLE NMI, F2 TO REBOOT | When BIOS detects a non-maskable interrupt condition during boot, this will allow you to disable the NMI and continue to boot; or you can reboot the system with the NMI enabled |
| Press TAB to show POST screen | System OEM’s may replace the Award BIOS POST display with their own proprietary display. Including this message in the OEM display permits the operator to switch between the OEM display |
| Primary master hard disk fail | POST detects an error in the primary master IDE hard drive |
| Primary slave hard disk fail | POST detects an error in the secondary master IDE hard drive |
| RAM PARITY ERROR – CHECKING FOR SEGMENT… | Indicates a parity error in RAM |
| Resuming from disk, Press TAB to show POST screen | Award offers a save-a-disk feature for notebook computers. This message may appear when the operator restarts the system after a save-to-disk shutdown. See the Press Tab…message earlier for a description of this feature |
| Secondary master hard disk fail | POST detects an error in the secondary master IDE hard drive |
| Secondary slave hard disk fail | POST detects an error in the secondary slave IDE hard drive |
| Should Be Empty But EISA Board Found | A valid board ID was found in a slot that was configured as having no board ID |
| Should Have EISA Board But Not Found | The board installed is not responding to the ID request, or no board ID has been found in the indicated slot |
| Slot Not Empty | Indicates that a slot designated as empty by the EISA configuration utility actually contains a board |
| SYSTEM HALTED. (CTRL-ALT-DEL) TO REBOOT… | Indicates the present boot attempt has been aborted and the system must be rebooted. Press and hold down the Ctrl and Alt keys and press Del |
| Wrong Board In Slot | The board ID does not match the ID stored in the EISA nonvolatile memory |