STC12系列单片机的C51串口通讯程序，实现与电脑的简单字符串的通讯，PC端用VB程序发送字符串，单片机接收数据，并显示在LCD屏幕上，当有特定字符时，单片机向PC发送LCD屏幕上显示的字符串-STC12 Series MCU C51 serial communications procedures, simple computer communication, PC end of the string to a VB program to send the string microcontr