Acer Altos R710 manual Checkpoint, Beep Code, Description

			187
Checkpoint	Beep Code	Description
Code
14h		Verify that the 8742 keyboard controller is
		responding. Send a self-test command to
		the 8742 and wait for results. Also read the
		switch inputs from the 8742 and write the
		keyboard controller command byte.
16h	1-2-2-3	Verify that the ROM BIOS checksums to
		zero.
17h		Initialize external cache before autosizing
		memory.
18h		Initialize all three of the 8254 timers. Set the
		clock timer (0) to binary count, mode 3
		(square wave mode), and read/write LSB
		then MSB. Initialize the clock timer to zero.
		Set the RAM refresh timer (1) to binary
		count, mode 2 (Rate Generator), and read/
		write LSB only. Set the counter to 12H to
		generate the refresh at the proper rate. Set
		sound timer (2) to binary count, mode 3,
		and read/write LSB, then MSB.
1Ah		Initialize DMA command register with these
		settings:
		1. Memory to memory disabled
		2.	Channel 0 hold address disabled
		3.	Controller enabled
		4.	Normal timing
		5.	Fixed priority
		6.	Late write selection
		7.	DREQ sense active
		8.	DACK sense active low

Initialize all 8 DMA channels with these settings:

1.Single mode

2.Address increment

3.Auto initialization disabled (channel 4 - Cascade)

4.Verify transfer