54LS257A DM54LS257B DM74LS257B 54LS258A DM54LS258B.
DM54LS258B - TRI-STATE Quad 2-Data Selectors/Multiplexers
54LS257A DM54LS257B DM74LS257B 54LS258A DM54LS258B DM74LS258B TRI-STATE Quad 2-Data Selectors Multiplexers June 1989 54LS257A DM54LS257B DM74LS257B .