Difference between revisions of "Databar decoding"
(Created page with "==Intro== [https://www.alchemistowl.org/pocorgtfo/pocorgtfo05.pdf PoC||GTFO 12] contains two pages (pp53-54) of giant barcodes as a puzzle: 600px[...") |
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The pages are available in high resolution [http://wiki.yobi.be/images/archive/4/40/20160622100722%21Pocorgtfo12-53.png here] and [http://wiki.yobi.be/images/archive/0/01/20160622100656%21Pocorgtfo12-54.png here]. |
The pages are available in high resolution [http://wiki.yobi.be/images/archive/4/40/20160622100722%21Pocorgtfo12-53.png here] and [http://wiki.yobi.be/images/archive/0/01/20160622100656%21Pocorgtfo12-54.png here]. |
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| + | ==Identification== |
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| + | The hardest part was to find which obscure format was used. |
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| + | <br>Initially I tried to parse manually the barcode: we easily see start and stop sequences, pulse widths being unit or double, and and some repetitions 7-unit large. But I couldn't go further. |
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| + | The revelation came when I stumbled upon this example: |
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| + | [[File:Pocorgtfo12-sample.jpg]] |
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| + | It's taken from http://www.mainbyte.com/ti99/hardware/oscar/oscar.html where we learn about Oscar, a "databar" optical reader meant to input programs into computers: |
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| + | [[File:Pocorgtfo12-databar.jpg]] |
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| + | The [http://www.mainbyte.com/ti99/hardware/oscar/oscar_man.pdf manual (pdf)] refers to several supported computers of the 80' : Atari 1200XL/1400XL, Atari 400/600/800, Commodore Pet, Commodore VIC 20/64, TI99/4A, TRS 80. Regarding the computer it acts as an ordinary cassette reader. |
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| + | ==Patent== |
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| + | Oscar was produced by Databar Corporation. |
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| + | <br>Looking a [https://patents.google.com/?assignee=Databar+Corporation patents from Databar Corporation], we can find two describing the Oscar reader, perfect! |
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| + | <br>The most relevant one for us is [https://www.google.com/patents/US4550247 US4550247A] which is easier to read [https://patentimages.storage.googleapis.com/pdfs/US4550247.pdf as pdf]. |
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| + | Note that both patents have expired. |
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| + | [[File:Pocorgtfo12-US4550247-1.png|600px]][[File:Pocorgtfo12-US4550247-5.png|600px]] |
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Revision as of 12:38, 22 June 2016
Intro
PoC||GTFO 12 contains two pages (pp53-54) of giant barcodes as a puzzle:
The pages are available in high resolution here and here.
Identification
The hardest part was to find which obscure format was used.
Initially I tried to parse manually the barcode: we easily see start and stop sequences, pulse widths being unit or double, and and some repetitions 7-unit large. But I couldn't go further.
The revelation came when I stumbled upon this example:
It's taken from http://www.mainbyte.com/ti99/hardware/oscar/oscar.html where we learn about Oscar, a "databar" optical reader meant to input programs into computers:
The manual (pdf) refers to several supported computers of the 80' : Atari 1200XL/1400XL, Atari 400/600/800, Commodore Pet, Commodore VIC 20/64, TI99/4A, TRS 80. Regarding the computer it acts as an ordinary cassette reader.
Patent
Oscar was produced by Databar Corporation.
Looking a patents from Databar Corporation, we can find two describing the Oscar reader, perfect!
The most relevant one for us is US4550247A which is easier to read as pdf.
Note that both patents have expired.
