ASCII conversion into hexadecimal number, single

代码说明：

ASCII码转换成十六进制数 ,单字节ＢＣＤ码小数转换成单字节十六进制小数,双字节十六进制小数转换成双字节ＢＣＤ码小数,单字节十六进制数转换成双字节ASCII码 -ASCII conversion into hexadecimal number, single-byte BCD decimal converted into single-byte hexadecimal minority. double-byte hexadecimal decimal converted into double byte BCD minority. single-byte hexadecimal number into double byte ASCII, etc.