Intel 820E manual ISA Bridge Checklist, Checklist Items, ICH2 AD22 / ISA

						Intel® 820E Chipset
		R
			Checklist Items		Recommendations	Reason/Effect
			Cable Detect*		• Host Side/Device Side Detection:	The 10 kΩ resistor to GND prevents GPI
					 Connect the IDE pin PDIAG/CBLID	from floating, if no devices are present on
						either IDE interface. Allows the use of
					to an ICH2 GPIO pin. Connect a
						3.3 V GPIOs that are not 5 V tolerant.
					10 kΩ resistor to GND on the signal
					line.	Note: All ATA66/100 drives can detect
					• Device-side detection:	cables.
					 Connect a 0.04 ∝ F capacitor from	See Figure 46.
					the IDE pin PDIAG/CBLID to GND.	See Figure 47.
					No ICH2 connection
	Note: The maximum trace length from the ICH2 to the ATA connector is 8 inches.
Table 42. ISA Bridge Checklist
			Checklist Items		Recommendations		Reason/Effect
			ICH2 GPO[21] / ISA	Connect ICH2 GPO[21] to ISA NOGO input.
			NOGO input	If GPO[21] is not available on the ICH2, any other GPO that defaults
				high in the system can be used. GPO[21] is the only ICH2 GPO that
				defaults high.
			ICH2 AD22 / ISA	Connect ICH2 AD22 to the ISA IDSEL input.
			IDSEL input

Design Guide 133