INT 21 - Phar Lap 386/DOS-Ext VMM v3.0 - READ PROTMODE REGS AFTER SFTWARE INT

	AX = 2538h
	DS:EBX -> buffer for registers (see #01368)
	ECX = register record to retrieve
	    00h first interrupt state
	    01h next interrupt state
		EDX = handle for current interrupt state
Return: CF clear if successful
	    DS:EBX buffer filled
	    EDX = handle of current interrupt state
	    ESI = number of interrupt which occurred
	CF set on error
	    EAX = error code
		81h invalid handle in EDX
		83h register saving not enabled
		84h no more interrupt states
SeeAlso: AX=2527h,AX=2528h