用c语言编写的4*4键盘输入检测。用AT89C51单片机做控制芯片，程序用keil编写，实验仿真有protel99se实现，已验证成功，该文件中有源程序和仿真文件。 -With the c language of 4* 4 keyboard input detection. To do with the AT89C51 microcontroller control chip, the program using keil write, experimental simulation

用c语言编写的一键多功能按键识别。用AT89C51单片机做控制芯片，程序用keil编写，实验仿真有protel99se实现，已验证成功，该文件中有源程序和仿真文件。-Using c language identification of a key multi-function buttons. To do with the AT89C51 microcontroller control chip, the program using keil write, experimental simula

用c语言编写的电子琴。用AT89C51单片机做控制芯片，程序用keil编写，实验仿真有protel99se实现，已验证成功，该文件中有源程序和仿真文件。 -With the c language of the keyboard. To do with the AT89C51 microcontroller control chip, the program using keil write, experimental simulation has protel99se realized, h

用c语言编写的点阵式LED简单图形显示。用AT89C51单片机做控制芯片，程序用keil编写，实验仿真有protel99se实现，已验证成功，该文件中有源程序和仿真文件。 -With the c language of the dot matrix LED simple graphic display. To do with the AT89C51 microcontroller control chip, the program using keil write, experimental