This part is a kind of semiconductor called 74266.

Function of this product has Quad 2-Input Exclusive NOR Gate.

Manufacturers : Motorola Semiconductor

Image and pinout :

Some of the text within the PDF file :

SN54/74LS266 QUAD 2-INPUT EXCLUSIVE NOR GATE QUAD 2-INPUT EXCLUSIVE NOR GATE LOW POWER SCHOTTKY VCC 14 13 12 * 11 10 * 9 8 J SUFFIX CERAMIC CASE 632-08 14 1 * 1 2 3 4 * 5 6 7 GND * OPEN COLLECTOR OUTPUTS 14 1 N SUFFIX PLASTIC CASE 646-06 TRUTH TABLE IN A L L H H B L H L H OUT Z H L L H 14 1 D SUFFIX SOIC CASE 751A-02 ORDERING INFORMATION SN54LSXXXJ SN74LSXXXN SN74LSXXXD Ceramic Plastic SOIC GUARANTEED OPERATING RANGES Symbol VCC TA VOH IOL Supply Voltage Operating Ambient Temperature Range Output Voltage High Output Current Low Parameter 54 74 54 74 54, 74 54 74 Min 4.5 4.75 – 55 0 Typ 5.0 5.0 25 25 Max 5.5 5.25 125 70 5.5 4.0 8.0 Unit V °C V mA FAST AND LS TTL DATA 5-1 SN54/74LS266 DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless [ ... ]

74266 PDF Datasheet Download