This part is a kind of semiconductor called 27C64.

Function of this product has 64K (8K x 8) CMOS EPROM.

Manufacturers : Microchip Technology

Image and pinout :

Some of the text within the PDF file :

27C64 64K (8K x 8) CMOS EPROM FEATURES • High speed performance - 120 ns access time available • CMOS Technology for low power consumption - 20 mA Active current - 100 µA Standby current • Factory programming available • Auto-insertion-compatible plastic packages • Auto ID aids automated programming • Separate chip enable and output enable controls • High speed “express” programming algorithm • Organized 8K x 8: JEDEC standard pinouts - 28-pin Dual-in-line package - 32-pin PLCC Package - 28-pin SOIC package - Tape and reel • Available for the following temperature ranges - Commercial: 0˚C to +70˚C - Industrial: -40˚C to +85˚C PACKAGE TYPES DIP/SOIC VPP A12 A7 A6 A5 A4 A3 A2 A1 A0 O0 O1 O2 VSS •1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 [ ... ]

27C64 PDF Datasheet Download