用Protel软件设计PCB文件。文档包括pcb布线技巧，pcb设计技巧和常见错误解决方法-PCB using Protel software design document. Documents including pcb wiring skills, pcb design techniques and common error solutions

具有记忆以及错误报警功能的密码锁的protel原理图 c源码-Has the memory and error reporting function of combination lock c source code

介绍Altium Dsigner 中出现错误的类型，非常适合初学者。-Altium Dsigner introduced an error of type, very suitable for beginners.