Acer Altos R710 manual 190

190		Appendix D: BIOS POST Checkpoint Codes
Checkpoint	Beep Code	Description
Code
49h		Perform these tasks:
		1. Size the PCI bus topology and set bridge
		bus numbers
		2. Set the system max bus number
		3. Write a 0 to the command register of
		every PCI device
		4. Write a 0 to all 6 base registers in every
		PCI device
		5. Write a -1 to the status register of every
		PCI device
		6. Find all IOPs and initialize them.
4Ah		Initialize all video adapters in system.
4Bh		Initialize QuietBoot if it is installed. Enable
		both keyboard and timer interrupts (IRQ0
		and IRQ1). If your POST tasks require inter-
		rupts off, preserve them with a PUSHF and
		CLI at the beginning and a POPF at the end.
		If you change the PIC, preserve the existing
		bits.
4Ch		Shadow video BIOS ROM if specified by
		Setup, and CMOS is valid and the previous
		boot was OK.
4Eh		Display copyright notice.
4Fh		Initialize MultiBoot. Allocate memory for
		old and new MultiBoot history tables.
50h		Display CPU type and speed.
51h		Checksum CMOS and initialize each EISA
		slot with data from the initialization data
		block.
52h		Verify keyboard reset.
54h		Initialize keystroke clicker if not enabled in
		Setup.
55h		Enable USB devices.