D-Link DWL-G820 rev A1

Overview
"8WAPG08..2A1" is silkscreened on the board.

Probable PSU(s)
The power supply included with the US distributed units looks to be a JENTEC JTA0302A.

Links of Interest

 * On the OpenWrt Wiki's (old) D-Link hardware table
 * On the OpenWrt Forums

Serial Pinouts
It seems to be a standard Alpha pinout.. JP2 (RxD)      (3.3) (GND) (TxD)