This part is a kind of semiconductor called Z86319.

Function of this product has PS/2 MOUSE CONTROLLER.

Manufacturers : Zilog

Image and pinout :

Some of the text within the PDF file :

PRELIMINARY PRODUCT SPECIFICATION 1 Z86319 PS/2 MOUSE CONTROLLER FEATURES 1 Device Z86319 ROM (KB) 2 RAM* (Bytes) 125 I/O Lines 13 Voltage Range 4.5V to 5.5V s P24-P27 Can Be Configured with a Voltage Divider During Input Mode On-Chip Oscillator (Tolerance = ±10%) Fast Instruction Pointer: 1.5 µs @ 4 MHz ESD Protection Circuitry Hardwired Watch-Dog Timer (WDT) Excellent System Level EMI/EFT/ESD s s Note: *General-Purpose (144K Total RAM) s s 0°C to + 40°C Operating Temperature Range Low-Power Consumption: 25 mW (Typical) s s s GENERAL DESCRIPTION The Z86319 is a member of the Z8 family of CMOS microcontrollers architecture to be used in mouse applications. These devices offer on-board pull-up and pull-down resistors, a trip-point buffer to accommodate [ ... ]

Z86319 PDF Datasheet Download