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Years ago, I called an earlier edition of this invaluable and I see no reason to change my view. Recommended."

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Personal Computer World

"To any micro owner who wants to know what this comms business is all about, [Communications & Networks] is certainly one of the best around. ... Croucher is not only knowledgable about his subject, he's interested in it and communicates that interest to you. "

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"There are few books about which explain as accurately and comprehensively as [Communications & Networks] does what communications are all about. The glossary is excellent."

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Emma Tyrrall
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"Good documentation is important for any software, but even more so for an operating system - the documentation [for DOS 386 Professional] has some exceptionally clear explanations. Altogether, the documentation is an example of the right way of doing things, and other software manufacturers would do well to take note."

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I heartily recommend it to students of commercial flight, if only as a souvenir of their efforts... "

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AMI POST Codes

Note: Not all POST codes are included below - the latest information is in the The BIOS Companion, which contains over 100 pages of them.


POST Procedures - Feb 91

NMI Disable NMI interrupt line to the CPU is disabled by setting bit 7 I/O port 70h (CMOS)
Power On Delay Once the keyboard controller gets power, it sets the hard and soft reset bits.  Check the keyboard controller or clock generator if a failure occurs
Initialize Chipsets Check the BIOS, CLOCK and chipsets
Reset Determination The BIOS reads the bits in the keyboard controller to see if a hard or soft reset is required (a soft reset will not test memory above 64K).  Failure could be the BIOS or keyboard controller
ROM BIOS Checksum The BIOS performs a checksum on itself and adds a preset factory value that should make it equal to 00.  If a failure occurs, check the BIOS chips
Keyboard Test A command is sent to the 8042 keyboard controller which performs a test and sets a buffer space for commands.  After the buffer is defined the BIOS sends a command byte, writes data to the buffer, checks the high order bits of the internal keyboard controller and issues a No Operation (NOP) command
CMOS Shutdown byte in CMOS RAM offset 0F is tested, the BIOS checksum calculated and diagnostic byte 0E updated before the CMOS RAM area is initialized and updated for date and time.  Check the RTC and CMOS chip or battery if a failure occurs
DMA (8237) and PIC (8259) Disable The DMA and Programmable Interrupt Controller are disabled before the POST proceeds and further.  Check the 8237 or 8259 chips if a failure occurs
Video Disable The video controller is disabled and port B initialized.  Check the video adapter if a failure occurs
Chipset Initialized and Memory Detected Memory addressed in 64K blocks.   Failure would be in the chipset.  If all memory is not seen, failure could be in a chip in the block after the last one seen
PIT Test The timing functions of the 8254 Programmable Interrupt Timer are tested.  The PIT and RTC chips normally cause errors here
Memory Refresh PIT's ability to refresh memory is tested.  If an XT, DMA controller #1 handles this.  Failure is normally the PIT (8254) in AT's or the 8237, DMA #1, in XT's
Address Line Test the address lines in the first 64K of RAM.  If a failure occurs, an address line may be the problem
Base 64K Data patterns are written to the first 64K of RAM, unless there is a bad RAM chip in which case you will get a failure
Chipset Initialization The PIT, PIC and DMA controllers are initialized
Set Interrupt Table Interrupt vector table used by PIC is installed in low memory, the first 2K
8042 Keyboard Controller Check The BIOS reads the buffer area in the keyboard controller I/O port 60.  Failure here is normally the keyboard controller
Video Tests The type of video adapter is checked for, then a series of tests are performed on the adapter and monitor
BIOS Data Area The vector table is checked for proper operation and video memory verified before protected mode tests are entered into.   This is done so that any errors found are displayed on the monitor
Protected Mode Tests Perform reads and writes to all memory locations below 1MB.  Failure at this point indicate a bad RAM chip, the 8042 Keyboard Controller or a data line
DMA Chips The DMA registers are tested using a data pattern
Final Initialization these differ with each version.   Typically, the floppy and hard drives are tested and initialized and a check is made for serial and parallel devices.  The information gathered is then compared against the contents of the CMOS and you will see the results of any failures on the monitor
BOOT The BIOS hands over control to the Int 19 bootloader.  This is where you would see error messages such as non-system disk

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 Text Messages

Bad PnP Serial ID Checksum The Serial ID checksum of a PnP card is invalid
Floppy Disk Controller Resource Conflict The floppy drive controller had requested a resource that is already in use
NVRAM Checksum Error - NVRAM Cleared The extended system configuration data (ESCD) was reinitialized because of an NVRAM checksum error.  Clear CMOS and ESCD RAM and reboot
NVRAM Cleared By Jumper The Clear CMOS jumper has been moved to the Clear position.  CMOS RAM and ESCD have been cleared
NVRAM Data Invalid - NVRAM Cleared Invalid data found in the ESCD, which might mean that you have changed devices in the system.  When this message is displayed, the BIOS has already rewritten the ESCD with current configuration data
Parallel Port Resource Conflict The parallel port requested a resource that is already in use
PCI Error Log is Full More than 15 PCI conflict errors have been detected and no additional PCI errors can be logged
PCI I/O Port Conflict Two devices requested the same I/O address, resulting in a conflict
PCI IRQ Conflict Two devices requested the same IRQ, resulting in a conflict
PCI Memory Conflict Two devices requested the same memory resource, resulting in a conflict
Primary Boot Device Not Found Two designated primary boot device (hard disk, floppy disk drive, CD-ROM drive) could not be found
Primary IDE Controller Resource Conflict The primary IDE controller has requested a resource that is already in use
Primary Input Device Not Found The designated primary input device (keyboard, mouse, or other device if input is redirected) could not be found
Secondary IDE Controller Resource Conflict The secondary IDE controller has requested a resource that is already in use
Serial Port 1 Resource Conflict Serial port 1 has requested a resource that is already in use
Serial Port 2 Resource Conflict Serial port 2 has requested a resource that is already in use
Static Device Resource Conflict A card that is not Plug-and-Play ISA has requested a resource that is already in use
System Board Device Resource Conflict A card that is not Plug-and-Play ISA has requested a resource that is already in use
A20 Error Gate A20 on the keyboard controller is not working
Address line Short Error in the address decoding circuitry on the motherboard
CMOS Battery State Low The battery power is low; replace the battery
CMOS Checksum Invalid After CMOS RAM values are saved, a checksum value is generated for error checking.  The previous value is different from the current value
Run Setup CMOS system options not set.  The values stored in CMOS RAM are either corrupt or nonexistent.  Run Setup
CMOS Display Type Mismatch The video type in CMOS RAM does not match the type detected by the BIOS. Run Setup
CMOS Memory Size Mismatch The amount of memory on the motherboard is different from the amount indicated in CMOS RAM.  Run Setup
CMOS Time and Date Not Set run Setup to set the time and date in the CMOS RAM
Diskette Boot Failure The boot disk in drive A: is corrupt.  It cannot be used to boot the system.  Use another boot disk and follow the screen instructions
DMA Error Error in the DMA controller
DMA #1 Error Error in the first DMA controller
DMA #2 Error Error in the second DMA controller
FDD Controller Failure The BIOS cannot communicate with the floppy disk drive controller.   Check all appropriate cables and connections
HDD Controller Failure The BIOS cannot communicate with the hard disk drive controller.   Check all appropriate cables and connections
Insert Bootable Media The BIOS cannot find a bootable medium.  Insert a bootable floppy disk or CD-ROM
INTR #1 Error Interrupt controller 1 failed POST
INTR #2 Error Interrupt controller 2 failed POST
Invalid Boot Diskette The BIOS can read the disk in floppy drive A:, but cannot boot the system from it.  Use another boot disk
KB/Interface Error There is an error in the keyboard connector
Keyboard Error There is a timing problem with the keyboard
Keyboard Stuck Key Detected A stuck keyboard key was detected
Off Board Parity Error Parity error in memory installed in an expansion slot.  The format is: OFF BOARD PARITY ERROR ADDR (HEX) = (XXXX), where XXXX is the hex address where the error occurred
On Board Parity Error Parity error in memory installed on the motherboard.  The format is: ON BOARD PARITY ERROR ADDR (HEX) = (XXXX), where XXXX is the hex address where the error occurred
Parity Error Parity error in system memory at an unknown address
System halted An error caused the computer to halt
Timer Channel 2 Error There is an error in counter/timer 2
Uncorrectable ECC Error An uncorrectable ECC memory error was detected
Undetermined NMI An undetermined NMI was detected
Memory parity Error at xxxxx Memory failed.  If the memory location can be determined, it is displayed as xxxxx.  If not, the message is Memory Parity Error ????.
I/O Card Parity Error at xxxxx An expansion card failed.  If the address can be determined, it is displayed as xxxxx.  if not, the message is I/O Card Parity error ????
DMA Bus Timeout A device has driven the bus signal for more than 7.8 microseconds

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 POST Codes Pre April 1990

01 NMI is disabled and the i286 register test is about to start
02 i286 register test has passed
03 ROM BIOS checksum test (32Kb from F8000h) passed OK
04 8259 programmable interrupt controller has initialized OK
05 CMOS interrupt disabled
06 Video system disabled and the system timer checks OK
07 8253/4 programmable-interval timer test OK
08 Delta counter channel 2 OK
09 Delta counter channel 1 OK
0A Delta counter channel 0 OK
0B Parity status cleared
0C The refresh and system timer check OK
0D Refresh check OK
0E Refresh period checks OK
10 Ready to start 64KB base memory test
11 Address line test OK
12 64KB base memory test OK
13 System-interrupt vectors initialized
14 8042 keyboard controller checks OK
15 CMOS read/write test OK
16 CMOS checksum and battery OK
17 Monochrome video mode OK
18 CGA color mode set OK
19 Attempting to pass control to video ROM at C0000h
1A Returned from video ROM
1B Display memory read/write test OK
1C Display memory read/write alternative test OK
1D Video retrace test OK
1E Global equipment byte set for proper video operation
1F Ready to initialize video system
20 Video test OK
21 Video display OK
22 The power-on message is displayed
30 Ready to start the virtual-mode memory test
31 virtual memory mode test started
32 CPU has switched to virtual mode
33 Testing the memory address lines
34 Testing the memory address lines
35 Lower 1MB of RAM found
36 Memory size computation checks OK
37 Memory test in progress
38 Memory below 1MB is initialized
39 Memory above 1MB is initialized
3A Memory size is displayed
3B Ready to test the lower 1MB of RAM
3C Memory test of lower 1MB OK
3D Memory test above 1MB OK
3E Ready to shutdown for real-mode testing
3F Shutdown OK- now in real mode
40 Ready to disable gate A20
41 A20 line disabled successfully
42 Ready to start DMA controller test
4E Address line test OK
4F System still in real mode
50 DMA page register test OK
51 Starting DMA controller 1 register test
52 DMA controller 1 test passed, starting DMA controller 2 register test
53 DMA controller 2 test passed
54 Ready to test latch on DMA controller 1 and 2
55 DMA controller 1 and 2 latch test OK
56 DMA controller 1 and 2 configured OK
57 8259 programmable interrupt controller initialized OK
58 8259 programmable interrupt controller mask register OK
59 Master 8259 programmable interrupt controller mask register OK
5A Ready to check timer interrupts
5B Timer interrupt check OK
5C Ready to test keyboard interrupt
5D Error detected in timer or keyboard interrupt
5E 8259 programmable interrupt controller error
5F 8259 programmable interrupt controller OK
70 Start of keyboard test
71 Keyboard controller Ok
72 Keyboard tested OK
73 Keyboard global initialization OK
74 Floppy setup ready to start
75 Floppy controller setup OK
76 Hard disk setup ready to start
77 Hard disk controller setup OK
79 Ready to initialize timer data
7A Verifying CMOS battery power
7B CMOS battery verified OK
7D Analyzing CMOS RAM size
7E CMOS memory size updated
7F Send control to adapter ROM
80 Enable the setup routine if <Delete> is pressed
82 Printer data initialization is OK
83 RS-232 data initialization is OK
84 80x87 check and test OK
85 Display any soft-error message
86 Give control to ROM E0000h
87 Return from system ROM
00 Call the Int19 boot loader

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POST Codes After April 1990

 

01 NMI is disabled and the i286 register test is about to start
02 i286 register test has passed
03 ROM BIOS checksum test (32KB from E8000h) passed OK
04 Passed keyboard controller test with and without mouse
05 Chipset initialized...DMA and interrupt controller disabled
06 Video system disabled and the system timer checks OK
07 8254 programmable interval timer initialized
08 Delta counter channel 2 initialization complete
09 Delta counter channel 1 initialization complete
0A Delta counter channel 0 initialization complete
0B Refresh started
0C System timer started
0D Refresh check OK
10 Ready to start 64KB base memory test
11 Address line test OK
12 64KB base memory test OK
15 ISA BIOS interrupt vectors initialized
17 Monochrome video mode OK
18 CGA color mode set OK
19 Attempting to pass control to video ROM at C0000h
1A Returned from video ROM
1B Shadow RAM enabled
1C Display memory read/write test OK
1D Alternate display memory read/write test OK
1E Global equipment byte set for proper
1F Ready to initialize video system
20 Finished setting video mode
21 ROM type 27256 verified
22 The power-on message is displayed
30 Ready to start the virtual mode memory test
31 Virtual memory mode test started
32 CPU has switched to virtual mode
33 Testing the memory address lines
34 Testing the memory address lines
35 Lower 1MB of RAM found
36 Memory size computation checks OK
37 Memory test in progress
38 Memory below 1MB is initialized
39 Memory above 1MB is initialized
3A Memory size is displayed
3B Ready to test the lower 1MB of RAM
3C Memory test of lower 1MB OK
3D Memory test above 1MB OK
3E Ready to shutdown for real-mode testing
3F Shutdown Ok - now in real mode
40 Cache memory now on...Ready to disable gate A 20
41 A20 line disabled successfully
42 i486 internal cache turned on
43 Ready to start DMA controller test
50 DMA page register test OK
51 Starting DMA controller 1 register test
52 DMA controller 1 test passed, starting DMA controller 2 register test
53 DMA controller 2 test passed
54 Ready to test latch on DMA controller 1 and 2
55 DMA controller 1 and 2 latch test OK
56 DMA controller 1 and 2 configured OK
57 8259 programmable interrupt controller initialized Ok
70 Start of keyboard test
71 Keyboard controller OK
72 Keyboard test OK...Starting mouse interface test
73 Keyboard and mouse global initialization OK
74 Display setup prompt.. Floppy setup ready to start
75 Floppy controller setup OK
76 hard disk setup ready to start
77 Hard disk controller setup OK
79 Ready to initialize timer data
7A Timer data area initialized
7B CMOS battery verified OK
7E CMOS memory size updated
7F Enable setup routine if <Delete> is pressed
80 Send control to adapter ROM at C800h to DE00h
81 Return from adapter ROM
82 Printer data initialization is OK
83 RS-232 data initialization is OK
84 80x87 check and test OK
85 Display any soft error message
86 Give control to ROM at E0000h
A0 Program the cache SRAM
A1 Check for external cache
A2 initialize EISA adapter card slots
A3 Test extended NMI in EISA system
00 Call the INT19 boot loader

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2.2 BIOS

 

00 Flag test; Testing of the CPU
03 Register test
06 Chipset test; System hardware initialized
09 BIOS checksum tested
0C Page register tested
0F 8254 timer tested
12 Memory refresh initialization
15 8237 DMA controllers tested
18 8237 DMA initialization
1B 8259 PIC initialization
1E 8259 PIC chips tested
21 Memory refresh tested
24 Base 64 address tested
27 Base 64 memory tested
2A 8742 keyboard tested
2D MC146818 RTC/CMOS
30 Protected mode started
33 Memory sizing test
36 First protected mode test passed
39 First protected mode test failed
3C CPU speed calculation
3F Read 8742 hardware switches
42 Initialize interrupt vector area
45 Verify CMOS configuration
48 Test and initialize video system
4B Unexpected interrupt tested
4E Start second protected mode test
51 Verify LDT instruction
54 Verify TR instruction
57 Verify LSL instruction
5A Verify LAR instruction
5D Verify VERR instruction
60 Address line A20 test
63 Unexpected exception tested
66 Start third protected mode test
69 Address line tested
6A Scan DDNIL bits for null pattern
6C System memory tested
6F Shadow memory tested
72 Extended memory tested
75 Verify memory configuration
78 Display CMOS error messages
7B Copy system BIOS shadow memory
7E 8254 clock tested
81 MC146818 RTC tested
84 Keyboard test
87 Determine keyboard type
8A Stuck key test
8D Initialize hardware Interrupt vectors
90 Math co-processor tested
93 Determine COM ports available
96 Determine LPT ports available
99 Initialize BIOS data area
9C Fixed/floppy controller tested
9F Floppy disk tested
A2 Fixed disk tested
A5 External ROM screen; Check for external ROM's
A8 System key lock test
AE F1 error message test
AF System boot initialization
B1 Call to Interrupt 19 boot loader

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AMI Plus BIOS

 

00 Control to Interrupt 19
01 NMI disabled (Bit 7 of I/O port 70h)
02 286 register test over
03 ROM checksum OK
04 8259 PIC initialization disabled
05 CMOS Interrupt disabled
06 System timer (PIT) counting OK
07 Channel 0 of 8259 PIC test OK
08 DMA channel 2 of delta count test OK
09 DMA channel 1 of delta count test OK
0A DMA channel 0 of delta test count OK
0B Parity status cleared (DMA/PIT)
0C Refresh and system time check OK (DMA/PIT)
0D Refresh link toggling OK (DMA/PIT)
0E Refresh period ON/OFF 50% OK
10 About to start 64K memory
11 Address line tested OK
12 64K base memory tested OK
13 Interrupt vectors initialized
14 8042 keyboard controller tested
15 CMOS Read/Write test OK
16 CMOS checksum/battery tested
17 Monochrome mode set OK (6845)
18 Color (CGA) mode set OK (6845)
19 Video ROM search
1A Optional video ROM OK
1B Display memory Read/Write test OK
1C Alternate display memory OK
1D Video retrace check Ok
1E Global byte set for video Ok
1F Mode set for mono/color OK
20 Video test OK
21 Video display OK
22 Power on message display OK
30 Readying virtual mode memory test
31 Virtual mode memory test started
32 Processor in virtual mode
33 Memory address line test
34 Memory address line test
35 Memory below 1MB calculated
36 Memory size computation OK
37 Memory test in progress
38 Memory initialization  below 1MB
39 Memory initialization  above 1MB
3A Display memory size
3B Ready to start memory below 1MB
3C Memory test below 1MB OK
3D Memory test above 1MB OK
3E Ready to switch to real mode
3F Shutdown successful
40 Ready to disable gate A-20 (8042)
41 Gate A-20 disabled (8042)
42 About to test DMA controller (8237)
4E Address line test OK
4F Processor in real mode
50 DMA page register test OK
51 DMA unit-1 base register OK
52 DMA unit-1 channel register OK
53 DMA channel-2 base register test OK
54 About to test both units OK
55 F/F latch tests both units OK
56 DMA units 1 & 2 programmed OK
57 8259 PIC initialization OK
58 8259 PIC mask register check OK
59 Master 8259 PIC mask register OK
5A Check timer and keyboard Interrupt
5B PIT timer Interrupt OK
5C About to test keyboard Interrupt
5D ERROR! Timer/keyboard Interrupt
5E 8259 PIC Interrupt controller error
5F 8259 PIC Interrupt controller test OK
70 Start of keyboard test
71 Keyboard test OK
72 Keyboard test OK
73 Keyboard global data initialize (8042)
74 Floppy controller setup about to start
75 Floppy controller setup OK
76 Hard disk controller setup about to start
77 Hard disk controller setup OK
79 About to initialize timer data
7A Verify CMOS battery power
7B CMOS battery verification done
7D Analyze test results for memory
7E CMOS memory size update OK
7F Check optional ROM C0000h
80 Keyboard sensed to enable setup
81 Optional ROM control OK
82 Printer global data init OK
83 RS-232 global data init OK
84 80287 check/test OK
85 About to display soft error
86 Give control to system ROM E0000h
87 System ROM E0000h check over
00 Call to Interrupt 19 for boot loader

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AMI Color BIOS

 

00 Control to Int 19 boor loader
01 CPU flag test
02 Power-on delay
03 Chipset initialization
04 Soft/hard reset
05 ROM enable
06 ROM BIOS checksum
07 8042 keyboard controller tested
08 8042 keyboard controller tested
09 8042 keyboard controller tested
0A 8042 keyboard controller tested
0B 8042 protected mode tested
0C 8042 keyboard controller tested
0D 8042 keyboard controller tested, CMOS
0E CMOS checksum tested
0F CMOS initialization
10 CMOS/RTC status OK
11 DMA/PIC disable
12 DMA/PIC initialization
13 Chipset/memory initialization
14 8254 PIT timer tested
15 8254 PIT channel 2 timer tested
16 8254 PIT channel 1 timer tested
17 8254 PIT channel 0 timer tested
18 Memory refresh test (PIC)
19 Memory refresh test (PIC)
1A Check 15-microsecond refresh (PIT)
1B Check 30-microsecond refresh (PIT)
20 Base 64K memory tested
21 Base 64K memory parity tested
22 Memory Read/Write
23 BIOS vector table initialization
24 BIOS vector table initialization
25 Turbo check of 8042 keyboard controller
26 Global data table for keyboard controller; turbo
27 Video mode tested
28 Monochrome tested
29 Color (CGA) tested
2A Parity-enable tested
2B Optional system ROM's check start
2C Video ROM check
2D Reinitialize main chipset
2E Video memory tested
2F Video memory tested
30 Video adapter tested
31 Alternate video adapter tested
32 Alternate video adapter tested
33 Video mode tested
34 Video mode tested
35 Initialize BIOS ROM data area
36 Power-on message display
37 Power-on message display
38 Read cursor position
39 Display cursor reference
3A Display BIOS setup message
40 Start protected mode tested
41 Build mode entry
42 CPU enters protected mode
43 Protected mode Interrupt enable
44 Check descriptor tables
45 Check memory size
46 Memory Read/Write tested
47 Base 640K memory tested
48 Check 640K memory size
49 Check extended memory size
4A Verify CMOS extended memory
4B Check for soft/hard reset
4C Clear extended memory locations
4D Update CMOS memory size
4E Base RAM size displayed
4F Memory Read/Write test on 640K
50 Update CMOS on RAM size
51 Extended memory tested
52 Re-size extended memory
53 Return CPU to real mode
54 Restore CPU registers
55 A-20 gate disabled
56 BIOS vector recheck
57 BIOS vector check complete
58 Clear BIOS display setup message
59 DMA, PIT tested
60 DMA page register tested
61 DMA #1 tested
62 DMA #2 tested
63 BIOS data area check
64 BIOS data area checked
65 Initialize DMA chips
66 8259 PIC initialization
67 Keyboard tested
80 Keyboard reset
81 Stuck key and batch test
82 8042 keyboard controller tested
83 Lock key check
83 Compare memory size with CMOS
85 Password/soft error check
86 XCMOS/CMOS equipment check
87 CMOS setup entered
88 Reinitialize chipset
89 Display power-on message
8A Display wait and mouse check
8B Shadow any option ROM's
8C Initialize XCMOS settings
8D Reset hard/floppy drives
8E Floppy compare to CMOS
8F Floppy disk controller initialization
90 Hard disk compare to CMOS
91 Hard disk controller initialization
92 BIOS data table check
93 BIOS data check hat halfway
94 Set memory size
95 Verify display memory
96 Clear all Interrupts
97 Optional ROM's check
98 Clear all Interrupts
99 Setup timer data/RS232 base
9A RS232 test; Locate and test serial ports
9B Clear all Interrupts
9C NPU test
9D Clear all Interrupts
9E Extended keyboard check
9F Set numlock
A0 Keyboard reset
A1 Cache memory test
A2 Display any soft errors
A3 Set typematic rate
A4 Set memory wait states
A5 Clear screen
A6 Enable parity/NMI
A7 Clear all Interrupts
A8 Control to ROM at E0000
A9 Clear all Interrupts
AA Display configuration
00 Call to Interrupt 19 boot loader

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AMI Win BIOS

 

00 Control to Int 19 boot loader
01 Disable NMI
02 Power-on delay
03 Soft reset power-on
05 Disable cache
06 Uncompressed POST code
08 CMOS checksum
08 CMOS initialization
0A CMOS initialization for date and time
0B Initialization before keyboard batch
0C Batch command to keyboard controller
0D Verify batch command
0E Initialize after KB controller batch
0F Write KB command byte
10 Pin 23/24 block/unblock command
11 Check for <INS> key command
12 DMA/PIC disable
13 Chipset initialization
14 8254 timer test
19 Memory refresh test
20 Base 64K memory test
23 Set BIOS stack, setup before int. vector init
24 Interrupt vector initialization
25 Read input port of 9042 chip, clear password
26 Initialize global data for turbo switch
27 Initialize before setting video mode
28 Set video mode
2A Initialize BUS
2B Setup before operational video check
2C Control to optional video ROM
2D Proc. after optional video ROM routine
2E Display memory Read/Write test if no EGA/VGA
2F Display memory Read/Write test
30 Retrace check
31 Display alternate memory Read/Write check
32 Alternate display retrace check
34 Set display mode
37 Display power-on message
38 Initialize BUS types
39 Display BUS initialization error messages
3A Display the hit <DEL> message
3B Virtual modem memory test
40 Prepare descriptor tables
42 Enter virtual mode for memory test
43 Enable Interrupts for diagnostic mode
44 Initialize data to check memory wrap at 0:0
45 Check memory wrap, find total memory amount
46 Memory write test
47 640K base memory write test
48 Determine memory below 1MB
49 Determine memory above 1MB
4B Check for soft reset, clear memory below 1MB
4C Clear memory above 1MB
4D Save memory size
4E Display first 64K memory size
4F Sequential and random memory test
50 Displayed memory size
51 Above 1MB memory test
52 Save memory size information
53 Enter real mode
54 Disable gate A-20 line
57 Adjust memory size
58 Clear hit <DEL> message
59 DMA/PIC test
60 DMA #1 base register test
62 DMA #2 base register test
65 Program DMA unit 1 and 2
66 Initialize 8259 Interrupt controller
67 Keyboard test
7F Enable extended NMI sources
80 Stuck key and batch test
81 Keyboard controller test
82 Write command byte, initialize circular buffer
83 Lock key check
84 Compare memory size with CMOS
85 Password/soft error check
86 Programming before check
87 Execute CMOS setup
88 Programming after setup
89 Power-on display
8B Shadow main and video BIOS
8C Setup options after CMOS setup
8D Initialize mouse
8E Reset hard disk controller
8F Floppy setup
91 Hard disk setup
94 Base/extended memory size
95 Init. PCI/VLB BUS optional ROM's from C800
96 Initialize before C800 optional ROM control
97 Control to optional ROM
98 Processing after optional ROM control
99 Setup timer data area/printer base address
9A Set RS-232 base address
9B Initialize before NPU test
9C NPU initialization
9D Initialization after NPU test
9E Check extended KB, KB ID and num-lock
9F Issue keyboard ID command
A0 Reset keyboard ID flag
A1 Cache memory test
A2 Display and soft errors
A4 Program memory wait states
A5 Clear screen, enable parity NMI
A7 Init. needed before control to E000 ROM
A8 Control to E000 ROM
A9 Init. needed after control to E000 ROM
AA Display system configuration
B0 Uncompressed SETUP code for hot-key
B1 Copy any code to specific area
C2 Disable NMI, power-on delay
C5 Enable ROM, disable cache
C6 ROM BIOS checksum
C7 CMOS shutdown register test
C8 CMOS shutdown
CA Initialize CMOS date and time
CB Initialization before keyboard batch
CD BAT command to keyboard controller
CE Installation after keyboard controller batch
CF Write keyboard command byte
D1 Check for <INS> key command
D2 Disable DMA and Interrupt controllers
D3 Chipset initialization/auto detect memory
D4 Uncompressed RUNTIME code
D5 RUNTIME code uncompressed
DD Control to shadow RAM at F000:F000

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AMI Ez-Flex BIOS

 

01 NMI disabled; Start CPU flag test
02 Power on delay
03 Initialize system chipset
04 Check keyboard for soft/hard reset
05 Enable ROM
06 ROM BIOS checksum tested
07 8042 keyboard controller tested
08 8042 keyboard controller tested
09 8042 keyboard controller tested
0A 8042 keyboard controller tested
0B 8042 protected mode tested
0C 8042 keyboard controller tested
0D CMOS RAM shutdown register tested
0E CMOS checksum tested
0F CMOS initialization
10 CMOS/RTC status OK
11 Disable DMA and PIC
12 Video display disabled
13 Chipset and memory initialized
14 8254 PIT tested
15 PIT channel 2 tested
16 PIT channel 1 tested
17 PIT channel 0 tested
18 PIT memory refresh tested
19 PIT memory refresh tested
1A Check 15 microsecond refresh (PIT)
1B Base 64K memory tested
20 Address lines tested
21 Base 64K parity memory tested
22 Memory Read/Write tested
23 Perform setup's prior to initialization of the vector table
24 Initialize BIOS vector table in lower 1KB of system RAM
25 8042 keyboard controller tested
26 Global for keyboard controller tested
27 Perform setups for vector table initialization
28 Monochrome video mode tested
29 Video (CGA) color mode tested
2A Parity enable tested
2B Check for optional ROM's
2C Check for video ROM
2D Determine if EGA/VGA is installed
2E Video memory is tested if non EGA/VGA
2F Video memory tested
30 Video adapter tested
31 Alternate video memory tested
32 Alternate video adapter tested
33 Video mode tested
34 Video mode tested
35 BIOS ROM data area initialized
36 Power on display cursor set
37 Power on message displayed
38 Cursor position read
39 Display cursor reference
3A Display Setup message
40 Protected mode tested
41 Build descriptor tables
42 CPU enters protected mode
43 Protected mode interrupt enabled
44 Descriptor tables checked
45 Memory size checked
46 Memory read/Write tested
47 Base 640K memory tested
48 Memory below 1MB checked for
49 Memory above 1MB checked for
4A ROM BIOS data area checked
4B Memory below 1MB cleared for soft reset
4C Memory above 1MB cleared for soft reset
4D Update CMOS memory size
4E Display base 64K memory test
4F Memory test on base 640K performed
50 RAM size updated for shadow operation
51 Extended memory test performed
52 System is prepared for real mode
53 CPU is returned to real mode
54 CPU registers are returned to real mode
55 A20 gate disabled
56 BIOS data area rechecked
57 BIOS data area check complete
58 Setup message displayed
59 DMA register page tested
60 Display memory verified
61 DMA #1 tested
62 DMA #2 tested
63 Perform BIOS data area check
64 BIOS data area checked
65 DMA initialized
66 8259 PIC initialized
67 Keyboard tested
80 Keyboard reset
81 Check for stuck key and batch test
82 8042 keyboard controller tested
83 Lock key checked
84 Memory size compared to CMOS
85 Password and soft error checked
86 CMOS equipment checked performed
87 CMOS setup performed if selected
88 Main chipset reinitialized after CMOS setup
89 Power on message displayed
8A Mouse check and wait message displayed
8B Any ROM's attempted to be shadowed
8C System initialized through CMOS settings
8D Hard drives and floppy drives reset
8E Floppy disk setup compared to CMOS settings
8F Floppy controller initialized
90 Hard disks setup compared to CMOS settings
91 Hard disk controller initialized
92 BIOS data table checked
93 BIOS data table check complete
94 Memory size set
95 Display memory verified
96 All Interrupts cleared
97 Optional ROM's checked for
98 All Interrupts cleared
99 Timer data setup
9A Serial ports checked for
9B All Interrupts cleared
9C Math coprocessor checked
9D All Interrupts cleared
9E Extended keyboard checked
9F NumLock set on keyboard
A0 Keyboard reset
A1 Cache memory size tested
A2 Display any soft errors
A3 Typematic rate set
A4 Memory wait states set
A5 Display is cleared
A6 Parity and NMI enabled
A7 All Interrupts cleared
A8 System control is turned over to ROM at E0000
A9 All Interrupts cleared
AA Displayed configuration
00 Call to Interrupt 19 for boot loader

 



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