Appendix B: BIOS POST Codes
POST (hex)
74h
75h
76h
77h
78h
79h
7Ah
7Bh
7Ch
7Dh
7Eh
7Fh
Defi nition
Reserved
Detect and install all IDE devices: HDD, LS120, ZIP,
Reserved
Detect serial ports and parallel ports
Reserved
Reserved
Detect and install
Reserved
Reserved
Reserved
Reserved
1.Switch back to text mode if full screen logo is supported.
-If errors occur, report errors and wait for keys.
-If no errors occur or F1 key is pressed to continue: - Clear EPA or customization logo
80h
81h
82h
Reserved
Reserved
1.Call chipset power management hook
2.Recover the text font used by EPA logo (not for full screen logo)
3.If password is set, ask for password
83h
84h
85h
Save all data in stack back to CMOS
Initialize ISA PnP boot devices
1.USB fi nal initialization
2.NET PC: Build SYSID structure
3.Switch screen back to text mode
4.Set up ACPI table at top of memory
5.Invoke ISA adapter ROMs
6.Assign IRQs to PCI devices
7.Initialize APM
8.Clear noise of IRQs
86h
87h
88h
89h
90h
91h
92h
93h
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Read HDD boot sector information for Trend
