I think what you want is "Softstrip" which was developed by Cauzin
Systems (Waterbury, Connecticut) and introduced around 1985.
Softstrip was the first two-dimension barcode symbology, and it can
encode around 600 characters per square inch.
This information comes from Punched Cards to Bar Codes, by Benjamin
The Barcode Software Center
> Does anyone know the correct spelling of the high-density barcode system
> that was intended to allow source code or binaries to be printed in magazines?
> I thought it was "Cauzon" but I find nothing on the web about that.
> It was like a barcode but used *ey squares: 8-10 high,
> and as wide as the page.
> -- Jeffrey Jonas
> The original Dr. JCL and Mr .hide