allegro中的文件类型

.brd  Board file
.dra Editable Symbol file, e.g. package, mechanical, format, shape and flash 
symbols
.pad Padstack file
.psm Library file - package, this file can be used directly in board file
.osm Library file –format,
.bsm Library file–mechanical,
.fsm Library file - flash
.ssm Library file - shape
.mdd Module definition
.drl NC drill file
.scr Script file
.art Artwork file
.log A log file contains data on most automatic process in PCB Editor
.jrl Journal file, Record Allegro events