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15C8

Category: BIOS

INT 15 - SYSTEM - ENABLE/DISABLE PROCESSOR FUNCTIONS

	AH = C8h
	AL = function
	    00h disable L1 cache
	    01h enable L1 cache
	    ---models 90 and 95 only---
	    02h disable L2 cache
	    03h enable L2 cache
	    04h disable both caches
	    05h enable both caches
	    06h return status of both caches
	    07h-FFh Reserved
Return: CF set on error
	CF clear if successful
	AH = status (see #00527)
	For subfunction 06h only:
	    BL = status of L1 cache
		00h enabled
		01h disabled or not installed
		02h disabled due to test error (can not be enabled)
	    BH = status of L2 cache (same codes as BL)
Notes:	 supported by at least PS/2 70, 70/486, 80-A21, 90, 95
	call AH=C0h and examine bit 3 of feature byte 2 to check if this
	  function is supported.
	on a 486 system, any external caches must be disabled when the
	  on-chip cache (L1) is disabled.
SeeAlso: AH=C0h


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  Copyright 2000   by Ralf Brown     Updated Jul 2000