PORTIBM PC Portable (uses same BIOS as XT) 0258-0259 - Intel 82C212B "Neat" chipset - EMSsee Expanded Memory Specification emulation control
Range:	base address may be set to 0208, 0218, 0258, 0268, 02A8, 02B8, or 02E8
                                                                                

PORTIBM PC Portable (uses same BIOS as XT) 0258-0259 - ATIBM PC AT RAMBANK Memory Expansion Board - EXT MEMORY AND EMS-SUPPORT
Range:	base address may be set to 0218h, 0228h, 0238h, 0258h, 0268h, 0298h,
	  or 02A8h