I think NetBSD/alpha 1.3 does not support AlphaPC 164SX, because 164SX
has incompatible PCI/ISA bridge chip.

According to "DIGITAL Semiconductor AlphaPC 164SX Motherboard Technical
Reference Manual(EC-R57EA-TE)", 164SX has CY82C693U-NC for PCI/ISA
bridge.

Comparing 82378ZB and CY82C693U, I found that ELCRs are located on
different I/O address.

	Chip		ELCR location
	====================================================
	82378ZB		I/O 0x04d0, 0x04d1
	CY82C693U	control register index 0x03, 0x04
			(accessed through I/O 0x22 and 0x23)

Takao Shinohara