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