RC-4000 Computer Reference Manual: Document enhancement

Original version: Sat Mar 9 15:07:15 2019.               

This directory contains an enhancement of a bitmap one-up and two-up page scan of a historic computer manual copies here from the original at http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf.

The processing illustrated in this directory involved these steps:

• Read the original bitmap PDF file into Adobe Acrobat Professional release 2019.010.20069, apply the Enhance Scan and Recognize [English] Text feature, and save the file with suffix -ocr. The OCR (Optical Character Representation) is reasonably accurate, but each page certainly contains multiple misrecognized numbers and words. No attempt has been made to repair such errors.
• Develop a PDFLaTeX wrapper file, RC_4000_Reference_Manual_Jun69-ocr-1up.ltx, with about 10 minutes of experimentation to get the clipping regions reasonably correct. Typesetting that file with pdflatex produces the final one-up PDF file, RC_4000_Reference_Manual_Jun69-ocr-1up.pdf , where each original document page is on a complete page. Printing or viewing that document should match the original manual closely.
• Use open-source free software to extract a plain-text version of the enhanced PDF file, like this: pdftotext -layout RC_4000_Reference_Manual_Jun69-ocr-1up.pdf. The result is available here.