How many digital devices that were created in 1960 are still running today? Most digital devices back then were created using vacuum tubes. How many vacuum tube makers still exist? The military was buying vacuum tubes from Checkoslovakia in the 80's to keep the SAGE early warning system running. ref: http://en.wikipedia.org/wiki/Semi_Automatic_Ground_Environme... That's because there were no American manufacturers of vacuum tubes after the late 70's.

Sure, we still have the technical specifications for how to build it, but manufacturing the individual components would be a giant pain in the ass.