Award Software International
Elite BIOS Version 4.51PG

POST Codes

EISA POST codes are typically output to port address 300h.
ISA POST codes are output to port address 80h.

C0    Turn Off Chipset  OEM Specific-Cache control
      Cache

1     Processor Test 1  Processor Status (1FLAGS) Verification.
                        Tests the following processor status flags:
                          carry, zero, sign, overflow,
                        The BIOS sets each flag, verifies
                        they are set, then turns each flag
                        off and verifies it is off.

2     Processor Test 2  Read/Write/Verify all CPU registers
                        except SS, SP, and BP with data
                        pattern FF and 00.

3     Initialize Chips  Disable NMI, PIE, AIE, UEI, SQWV
                        Disable video, parity checking, DMA
                        Reset math coprocessor
                        Clear all page registers, CMOS shutdown byte
                        Initialize timer 0, 1, and 2, including set
                          EISA timer to a known state
                        Initialize DMA controllers 0 and 1
                        Initialize interrupt controllers 0 and 1
                        Initialize EISA extended registers.

4     Test Memory       RAM must be periodically refreshed to
      Refresh Toggle    keep the memory from decaying.  This
                        function ensures that the memory
                        refresh function is working properly.

5     Blank video,      Keyboard controller initialization.
      Initialize
      keyboard

6     Reserved

7     Test CMOS         Verifies CMOS is working correctly,
      Interface and     detects bad battery.
      Battery Status

BE    Chipset Default   Program chipset registers with power
      Initialization    on BIOS defaults.

C1    Memory presence   OEM Specific-Test to size on-board
      test              memory

C5    Early Shadow      OEM Specific-Early Shadow enable for
                        fast boot.

C6    Cache presence    External cache size detection
      test

8     Setup low memory  Early chip set initialization
                        Memory presence test
                        OEM chip set routines
                        Clear low 64K of memory
                        Test first 64K memory.

9     Early Cache       Cyrix CPU initialization
      Initialization    Cache initialization

A     Setup Interrupt   Initialize first 120 interrupt
      Vector Table      vectors with SPURIOUS_INT_HDLR and
                        initialize
                        INT 00h-1Fh according to INT_TBL

B     Test CMOS RAM     Test CMOS RAM Checksum, if bad, or
      Checksum          insert key pressed, load defaults.

C     Initialize        Detect type of keyboard controller
      keyboard          (optional)
                        Set NUM_LOCK status.

D     Initialize Video  Detect CPU clock.
      Interface         Read CMOS location 14h to find out
                        type of video in use.
                        Detect and Initialize Video Adapter.

E     Test Video        Test video memory, write sign-on
      Memory            message to screen.
                        Setup shadow RAM - Enable shadow
                        according to Setup.

F     Test DMA          BIOS checksum test.
      Controller 0      Keyboard detect and initialization

10    Test DMA
      Controller 1

11    Test DMA Page     Test DMA Page Registers.
      Registers

12-13   Reserved

14    Test Timer        Test 8254 Timer 0 Counter 2.
      Counter 2

15    Test 8259-1 Mask  Verify 8259 Channel 1 masked
      Bits              interrupts by alternately turning off
                        and on the interrupt lines.

16    Test 8259-2 Mask  Verify 8259 Channel 2 masked
      Bits              interrupts by alternately turning off
                        and on the interrupt lines.

17    Test Stuck        Turn off interrupts then verify no
      8259's Interrupt  interrupt mask register is on.
      Bits

18    Test 8259         Force an interrupt and verify the
      Interrupt         interrupt occurred.
      Functionality

19    Test Stuck NMI    Verify NMI can be cleared.
      Bits (Parity/IO
      Check)

1A                      Display CPU clock

1B-1E   Reserved

1F    Set EISA Mode     If EISA non-volatile memory checksum
                        is good, execute EISA initialization.
                        If not, execute ISA tests an clear
                        EISA mode flag.
                        Test EISA Configuration Memory
                        Integrity (checksum &amp; communication
                        interface).

20    Enable Slot 0     Initialize slot 0 (System Board).

21-2F   Enable Slots      Initialize slots 1 through 15.
      1-15

30    Size Base and     Size base memory from 256K to 640K
      Extended Memory   and extended memory above 1MB.

31    Test Base and     Test base memory from 256K to 640K
      Extended Memory   and extended memory above 1MB using
                        various patterns.
                        NOTE: This test is skipped in EISA
                        mode and can be skipped with ESC key
                        in ISA mode.

32    Test EISA         If EISA Mode flag is set then test
      Extended Memory   EISA memory found in slots
                        initialization.
                        NOTE:  This test is skipped in ISA
                        mode and can be skipped with ESC key
                        in EISA mode.

33-3B   Reserved

3C    Setup Enabled

3D    Initialize &amp;      Detect if mouse is present,
      Install Mouse     initialize mouse, install interrupt
                        vectors.

3E    Setup Cache       Initialize cache controller.
      Controller

3F    Reserved

BF    Chipset           Program chipset registers with Setup
      Initialization    values

40                      Display virus protect disable or
                        enable

41    Initialize        Initialize floppy disk drive
      Floppy Drive &amp;    controller and any drives.
      Controller

42    Initialize Hard   initialize hard drive controller and
      Drive &amp;           any drives.
      Controller

43    Detect &amp;          Initialize any serial and parallel
      Initialize        ports (also game port).
      Serial/Parallel
      Ports

44    Reserved

45    Detect &amp;          Initialize math coprocessor.
      Initialize Math
      Coprocessor

46    Reserved

47    Reserved

48-4D  Reserved

4E    Manufacturing     Reboot if Manufacturing POST Loop pin
      POST Loop or      is set.  Otherwise display any
      Display Messages  messages (i.e., any non-fatal errors
                        that were detected during POST) and
                        enter Setup.

4F    Security Check    Ask password security (optional).

50    Write CMOS        Write all CMOS values back to RAM and
                        clear screen.

51    Pre-boot Enable   Enable parity checker
                        Enable NMI, Enable cache before boot.

52    Initialize        Initialize any option ROMs present
      Option ROMs       from C8000h to EFFFFh.
                        NOTE:  When FSCAN option is enabled,
                        ROMs initialize from C8000h to
                        F7FFFh.

53    Initialize Time   Initialize time value in 40h: BIOS
      Value             area.

60    Setup Virus       Setup virus protect according to
      Protect           Setup

61    Set Boot Speed    Set system speed for boot

62    Setup NumLock     Setup NumLock status according to
                        Setup

63    Boot Attempt      Set low stack
                        Boot  via INT 19h.

B0    Spurious          If interrupt occurs in protected
                        mode.

B1    Unclaimed NMI     If unmasked NMI occurs, display
                        Press F1 to disable NMI, F2 reboot.

E1-EF   Setup Pages       E1- Page 1, E2 - Page 2, etc.

FF    Boot






































