TOSHIBA TC55B4256]-12/15/20 SILICON GATE BiCMOS .
TC55B4256J-20 - 256K x 4-Bit BiCMOS Static RAM
TC55B4256J-15 - 256K x 4-Bit BiCMOS Static RAM
TC55B4256J-12 - 256K x 4-Bit BiCMOS Static RAM
TC55B4256J - 256K x 4-Bit BiCMOS Static RAM
