FD

= Fade Down,图象衰减，逐渐消隐;

= Feedback Decoding, 回授译码;

= File Definition, 文件定义;

= File Description, 文件描述;

= File Directory, 文件目录;

= Flexible [Floppy] Disc, 软磁盘;

= Floating Divide, 浮点除法;

= Frequency Divider, 分频器