INT 50 - PCIBM PC Thuis Organizer Shell - COMPARE MEMORY
	AX = 0012h
	DS:SI -> source
	ES:DI -> destination
	CX = number of bytes to compare (0000h=until NUL string terminator???)
Return: AX = status
	    0000h same
	    FFFFh different
SeeAlso: AX=0011h