29 Apr
2006
29 Apr
'06
8:23 p.m.
Okay, here's one for you historians.
I know that many card readers used both optical as well as electrical
contact technology, but did any use air pressure to sense card holes?
This occurs to me because I've been listening to recordings of old piano
rolls--which used a vacuum system to sense holes--and did their job
remarkably well, considering that the technology's over 100 years old.
Just an idle mind wanting to be amused...
Cheers,
Chuck