AM9112DDC Ceramic 256 X 4, 16 pin, static RAM.  This ram is the "D" version which was the fastest ever made (250ns) speed.  It will replace the A  (500ns), B (400ns) and C (300ns) versions of the AM9112, which are slower speeds. As well as all variants of the Intel P2112, Hitachi HM2112,  Synertek SY2112, Mitsubishi M5L2112  and others.  This is the high end fastest ceramic version like the Intel C2112A-2, and that is why its stamped that way on the chip. These are unused parts here in my stock in the USA.  We do not sell Chinese Counterfeit junk.