First thing digged out while writing the bible

https://hackaday.io/project/6878-antti-bible

Sipsik(tm) standard has old roots, and is still in use in some form today!

Probably one of the oldest preserved photos from an Sipsik PCB: the LED board with 8 LEDS is an Sipsik(tm) board. It is single sided board made with heat transfer, some years before this photo was taken.