email was Mac something something

[Tom Jennings]

On Fri, 14 Jan 2005, John Foust wrote:

>> So... what's the chance of doing this with a solid-state laser?
>> Say 9 of them? The idea of high-speed papertape (sic) thrills me.
>> I know I'm sick, but I don't want to stop.
>
> Why stop at nine?  Optical scanning of a tape via linear CCD
> or video chip or reflected laser must be scads faster than
> mechanical methods (from pins in holes, to helical scan mag tape).

Well, I have a particular project in mind for that but I agree
with you -- why stop there?

> But why limit yourself to perpendicular rows?  Sounds like what
> you want is a dense 2D barcode, like the UPS and USPS codes,
> but somehow sequential, flowing, 2 1/2 D.

Well.. I simply hadn't considered anything else! But an N x M
array reading the tape, could do high density with redundancy and
correction, and make finding the edges of pits easy.

> The hard part is picking the medium, I'd think.  You want something
> that'll do a fast detectable change that'll keep over time,
> burnable by a power-enough laser.  They speak of mylar tape,
> but my TTY stuff is so old I've never seen it.  Will it detectably
> deform if you heat it?

I was thinking more generically here, 'thin mylar tape' from other
industries, but whatever.

> I've loved brainstorming about these sorts of barcoding schemes.
> It seems to me that it's a big missing hole in the convergence
> that everyone's always talking about.  There's few super-easy ways
> to move a URL from print automagically into a computer, and RFID
> seems almost clunky compared to burning microscopic bar codes all
> over the surface of objects.

Well my crazy project could in fact use something higher density than
old style!