V-3.1 New features：
1.Increase the working status indicator, which can quickly judge the working status
2.Increase the position of 3225 X1 active crystal oscillator. For individual motherboards with interference, you can choose to install the built-in crystal oscillator yourself.
3.Add P1 and P2 quick welding points on the back
4.Better than V2-B

V2-B version improvements:
1.Power saving design with DC-DC power supply chip,MP1471chip.
2. Better SMS Game compatibility.
3.Add P1 P2 label，Add 3MP1 jumper point.
4.High quality PCB than V1 and V2.

V2 version improvements:
1.The model of SRAM cache chip is changed from IS61WV6416-10TI to IS61LV6416-8TI, which is more power-saving, faster and has no image tearing.
2.The power supply is improved to AMS1117 3.3, the maximum load is 1.0A, and the operation is more stable.
3.Replacement of backlight drive circuit to reduce power consumption.
4.Welding marks are newly added to optimize the position of welding points, making welding easier.