cp
zero set if equal
carry set, argument is greater
neither, A is greater

cp 6
	(a-6)

;HL=L*E

    LD H, 0
    LD D, H
    LD B, 8
MULT:
    ADD HL,HL
    JR NC, NOADD
    ADD HL,DE
NOADD:
    DJNZ MULT