Tyan Computer TYAN S1668 Dram Installation, Voltage ID for Older Pentium Pro CPUs J10 and J20

3.10 DRAM Installation

The S1668 uses a 64-bit data path from memory to CPU and can accommodate up to 1024 MB of RAM. The mainboard supports standard, EDO (Extended Data Out) and ECC(Error Correcting Code) 72 pin SIMMS . All installed memory will be automatically detected so there is no need to set jumpers.

wSIMM modules must be installed in pairs.

wEach pair of SIMMs must be of the same size and type.

wThe mainboard supports 1, 2, 4, 8, 16x32 or 32MBx32 SIMMS.

wThe table on the following page shows some of the available memory configurations.

Voltage ID for Older Pentium Pro CPU's: J10 and J20

Most Pentium Pro CPU's will program the VRM to output

the correct voltage it requires, so these jumper are not important and should be left open. Some early versions of the Pentium Pro cannot program the VRM so you have to set these jumper manually.

J10 and J20 each have eight pins and are numbered as follows.

5	6	7	8	Pin #	4--8	3-7	2-6	1-5
				3.5V	on	on	on	on
				3.4V	on	on	on	off
				3.3V	on	on	off	on
1	2	3	4
				3.2V	on	on	off	off
				3.1V	on	off	on	on
				3.0V	on	off	on	off
				2.9V	on	off	off	on
				2.8V	on	off	off	off
				2.7V	off	on	on	on
				2.6V	off	on	on	off
				2.5V	off	on	off	on
				2.4V	off	on	off	off
				2.3V	off	off	on	on
				2.2V	off	off	on	off
				2.1V	off	off	off	on
				Default	off	off	off	off

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