PORTIBM PC Portable (uses same BIOS as XT) 0068 - C&T CHIPSETS - TURBO MODE CONTROL

Note:	  on Micronics 386-25/386-33/486-25 motherboards, setting this port to
	    00h enables full speed; setting it to C0h slows the system down by
	    a factor corresponding to the value programmed into the EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus).
	    interval timer 2 at ports 004Ah and 004Bh