This part is a kind of semiconductor called 28F256.

Function of this product has 256 Kilobit (32 K x 8-Bit) CMOS 12.0 Volt / Bulk Erase Flash Memory.

Manufacturers : Advanced Micro Devices

Image and pinout :

Some of the text within the PDF file :

FINAL Am28F256 256 Kilobit (32 K x 8-Bit) CMOS 12.0 Volt, Bulk Erase Flash Memory DISTINCTIVE CHARACTERISTICS s High performance 70 ns maximum access time s CMOS Low power consumption 30 mA maximum active current 100 µA maximum standby current No data retention power consumption s Compatible with JEDEC-standard byte-wide 32-Pin EPROM pinouts 32-pin PDIP 32-pin PLCC 32-pin TSOP s 10,000 write/erase cycles minimum s Write and erase voltage 12.0 V ±5% s Latch-up protected to 100 mA from –1 V to V CC +1 V s Flasherase Electrical Bulk Chip-Erase One second typical chip-erase s Flashrite Programming 10 µs typical byte-program 0.5 second typical chip program s Command register architecture for microprocessor/microcontroller compatible write interface [ ... ]

28F256 PDF Datasheet Download