21 Apr
1998
21 Apr
'98
12:55 a.m.
At 12:34 AM 4/21/98 -0400, Allison wrote:
Ah gads you guys do it the hard way. Take a stepper from something and
put a roller on it with a diameter such that one step will move the card
forward one column. Then all you need is one rows worth of
phototransistors. I forget the punched card orgainization but a parallel
port (printer) off a PC should be enough bits.
<snippage>
Oh the only difference with hole vs mark sense is
transmittance or
reflective sensing.
Ummm... I may wish to debate that just a tad...
Its been a rare mark sense card that I've seen to stuff 80 colums of data
in a 'standard' tab card form factor. Usually more like 36-40 to allow for
the timing marks and the nominally sloppy filling in of the infamous
'bubbles'.
-jim
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