むむむ、qcad demo version
http://www.ribbonsoft.com/qcad_downloads.html
* There is no functional difference between the demo version and the professional version of QCad.
* The demo version terminates after 10 minutes.
* It can be restarted and used for 100 hours in total
今見たら1回10分て、、、
後で別のcad探そう。