MD

= Macro Directory,宏目录;

= MacroData, 宏数据;

= Magnetic Disk, 磁盘;

= Magnetic Drum, 磁鼓;

= Maintenance Device, 维护设备;

= Memory Decrement, 存储器(地址)递减;

= Message Data, 信息[报文]数据;

= MoDe, 方式，式，型；状态；模，模式