Databar decoding

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Intro

PoC||GTFO 12 contains two pages (pp53-54) of giant barcodes as a puzzle:

Pocorgtfo12-53.pngPocorgtfo12-54.png

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:

Pocorgtfo12-sample.jpg

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:

Pocorgtfo12-databar.jpg

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.

Pocorgtfo12-US4550247-1.pngPocorgtfo12-US4550247-5.png