This part is a kind of semiconductor called DS1228.
Function of this product has +5V Powered Dual RS-232 Transmitter/Receiver.
Manufacturers : Dallas
Image and pinout :
Some of the text within the PDF file :
DS1228 DS1228 +5V Powered Dual RS-232 Transmitter/Receiver FEATURES PIN ASSIGNMENT C1+ V+ C1C2+ C2VT2OUT R2IN 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC GND T1OUT C1+ V+ R1IN C1R1OUT C2+ T1IN C2V1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC GND T1OUT R1IN R1OUT T1IN T2IN R2OUT • Operates from a single 5V power supply • Two drivers and two receivers • Meets all EIA RS-232-C specifications • On-board voltage doubler • On-board voltage inverter • + 30V input levels • + 9V output levels with + 5V supply • Low-power CMOS • Pin-compatible with the MAX 232 • Optional 16-pin SOIC surface mount package PIN DESCRIPTION C1+, C1 C2+, C2 V+, VT1IN, T2IN T1OUT, T2OUT R1IN, R2IN R1OUT, R2OUT VCC GND – – – – – – – – – Capacitor 1 Connections Capacitor 2 Connections + [ ... ]