出租车计价器，用单片机等的设计，用到系统需三块千进制计数器，均由四块74ls290芯片组合。3元五公里-You can lean it ,though run it ,maybe it not good enough,but you can see it .

VB源码，关于二进制、八进制、十进制和十六进制之间的转换。-VB source code, on the binary, octal, decimal and hexadecimal conversion between.