HT82M23A/HT82M23B/HT82M23C 3/5-Key USB+PS/2 Optica.
Holtek Semiconductor
HT82M23A - 3/5-Key USBPS/2 Optical Mouse Controller
HT82M23A/HT82M23B/HT82M23C 3/5-Key USB+PS/2 Optical Mouse Controller Features · Operating voltage: 4.4V~5.25V · Compatible with Microsoft Windows 2000.