Tony Duell <ard_at_p850ug1.demon.co.uk> wrote:
>Punched cards have one major design bug IMHO that's not shared by paper
>tape. There's no 'column reference' on a card.
>It's therefore almost impossible to make a hand-pulled card reader.
Come to think of it, perhaps a sub-$50 B/W QuickCam would make a
cheaper reader than a scanner. You could aim it at the card, in a
frame, and drive it by hand. Front-lighting and scanning can put
a non-card color behind the holes. Or you could back-light with
infrared LEDs and take advantage of chip-cam IR sensing. Unlike
phototransistor or mechanical solutions, it's not dependent on
particular card geometry.
I know the video/scanning route sounds like technological overkill.
What's wrong with that? :-) It reminds me of my day-dream to
rescue audio cassette data using PC sound card digitizing.
I like these novel solutions because they are less dependent on
esoteric hardware, and the core - the software - is more portable
and transportable into the future and to users who need it.
Sounds like Ethan has more spare time than I do, though!
- John
Jefferson Computer Museum <
http://www.threedee.com/jcm>
Received on Tue Apr 21 1998 - 11:19:26 BST