BUY SN74LS28 https://www.utsource.net/itm/p/8844124.html
Quadruple 2-input Positive-nor Buffers
Description: The SN74LS28 is a Quad 2-Input Positive-OR Gates integrated circuit from Texas Instruments. Features: Low power consumption High noise immunity High speed operation High output current High noise immunity Low input current Low input capacitance Low power dissipation Applications: Logic operations Data processing Signal processing Control systems Timing circuits Memory systems (For reference only)