4 ms·

( https://patents.google.com/patent/US4877983A/en https://patents.google.com/patent/US4877983A/en expired 2006, https://www.freepatentsonline.com/4877983.html h

by thro1 1y ago

( https://patents.google.com/patent/US4877983A/en https://patents.google.com/patent/US4877983A/en expired 2006, https://www.freepatentsonline.com/4877983.html https://www.freepatentsonline.com/4877983.html ) Is that similar: https://news.ycombinator.com/item?id=45600132 https://news.ycombinator.com/item?id=45600132 ?