Test

Beep

POST Routine Description

Point

Code

 

 

 

 

84h

 

Detect and install external parallel ports

 

 

 

85h

 

Initialize PC-compatible PnP ISA devices

 

 

 

86h

 

Re-initialize onboard I/O ports

 

 

 

87h

 

Configure mainboard configurable devices (optional)

 

 

 

88h

 

Initialize BIOS data area

 

 

 

89h

 

Enable non-maskable interrupts

 

 

 

8Ah

 

Initialize extended BIOS data area

 

 

 

8Bh

 

Test and initialize PS/2 mouse

 

 

 

8Ch

 

Initialize diskette controller

 

 

 

8Fh

 

Determine number of ATA drives (optional)

 

 

 

90h

 

Initialize hard drive controllers

 

 

 

91h

 

Initialize local-bus hard drive controllers

 

 

 

92h

 

Jump to UserPatch2

 

 

 

93h

 

Build MPTABLE for multi-processor boards

 

 

 

95h

 

Install CD ROM for boot

 

 

 

96h

 

Clear huge ES segment register

 

 

 

97h

 

Fix multi-processor table

 

 

 

98h

1-2

Search for option ROMs. Beeps on checksum failure

 

 

 

99h

 

Check for SMART drive (optional)

 

 

 

9Ah

 

Shadow option ROMs

 

 

 

9Ch

 

Set up power management

 

 

 

9Dh

 

Initialize security engine (optional)

 

 

 

9Eh

 

Enable hardware interrupts

 

 

 

9Fh

 

Determine number of ATA and SCSI drives

 

 

 

A0h

 

Set time of day

 

 

 

A2h

 

Check key lock

 

 

 

A4h

 

Initialize typematic rate

 

 

 

A8h

 

Erase F2 prompt

 

 

 

AAh

 

Scan for F2 keystroke

 

 

 

ACh

 

Enter SETUP

 

 

 

AEh

 

Clear boot flag

 

 

 

B0h

 

Check for errors

 

 

 

*If the BIOS detects error 2C or 2E, it displays an additional word-bitmap (xxxx) indicating the address line or bits that failed. For example, “2C 0002” means address line 1 (bit one set) has failed. “2E 1020” means data bits 12 and 5 (bits 12 and 5 set) have failed in the lower 16 bits.

Troubleshooting 91