Serial Port

From Sp305x wiki

The SPMP305x-chips have a serial port, which can be used for debugging purposes. There are multiple revisions of the mainboard. One of the incarnations has the serial port exposed as 2 test-points next to the main chip, which usually is located under the LCD.

On the SPMP chip, pin 112 is RxD and pin 113 is TxD.

To make use of these two points, you'll need a TTL->RS232-converter like the MAX2232 or an USB-solution like the FT232. The serial port runs at 115200 baud, no parity, 8 databytes, 1 stopbit.

Another revision of the mainboard also has the serial port exposed as testpoints, however, these are located at the bottom of the board.

Even if there are no testpoints to solder wires to, you can follow the traces from the SPMP serial pins and solder directly to the first component.

Erant: Will make pictures. GameKing II is one of the ones that has it at the bottom.