Parallel2usb

Fake Parallel Printer

This repo contains the design files for the Fake Printer tool: a hardware dongle with a DB-25 connector that plugs into the parallel printer port that was available on nearly all computers and equipment in the eighties and nineties.

Check out this blog post for a detailed description of the design, and build and usage instructions:

• Fake Parallel Printer - A Parallel Port Traffic Capturing Tool

There are 2 versions of the PCB. Revision 2 only uses 2 layers and doesn't stick out as much out of the device in which is plugged in. It's probably the best one to build. The firmware is designed to work for both PCB versions.

PCB v1

• KiCAD database of the PCB: ./parallel2usb_v1
• Schematic of PCB v1

PCB v2

WARNING: v2 hasn't been tested!!!

• KiCAD database of the PCB: ./parallel2usb_v2
• Schematic of PCB v2

A Digikey cart with all the components to populate version 2 of the PCB can be found here. Not all resistors and capacitor must be populated though. Check out the blog post for details.

Firmware

parallel2usb_hd_on.uf2 contains the compiled firmware for the Raspberry Pico.

To make changes and recompile yourself:

• set the PICO_SDK environment variable to the path of your locally installed Raspberry Pico SDK.

• Build the code:

  mkdir -p ./c/build
  cd ./c/build
  cmake ..
  make

• If all goes well, a new parallel2usb.uf2 will be waiting in ./c/build/parallel2usb.

Capturing Parallel Port Data

• Plug in the board into the host with the parallel port.
• Connect your PC to the board with a USB cable.
• Run python3 ./fake_printer.py -p <USB serial device> (Use -h for more options.)
• Issue a print operation on the host.
• A new file will be generated for each print operation

Converting a Parallel Port Captured File

• PCL: use Ghostscript

  ~/tools/ghostpcl-10.0.0-linux-x86_64/gpcl6-1000-linux-x86_64 -dNOPAUSE -sOutputFile=output.png -sDEVICE=png256 -g8000x8000 -r600x600 print_cap.pcl

• Epson ESC/P: use PrinterToPDF

  /opt/printerToPDF/bin/printerToPDF -o output -f /opt/printerToPDF/lib/PrinterToPDF/font2/Epson-Standard.C16 print_cap.esc_p

• Encapsulated Postscript: use Ghostscript and ImageMagick to add a background if necessary. Note that some scopes (TDS 684B) may emit a few chunks of comments that fake_printer.py will get with multiple-second delays, and they need to be concatenated together to form a valid eps file.

  gs -dSAFER -dBATCH -dNOPAUSE -dEPSCrop -sDEVICE=pngalpha -r300 -sOutputFile=ph1-zoomout.png ph1-zoomout.eps; convert -background black -alpha remove -alpha off ph1-zoomout.png ph1-zoomout.png

Conversions

• HP Infinium

./fake_printer.py --port=/dev/ttyACM0 -t 2 -v --prefix=hp_osc_ -s eps
inkscape -f ./hp_osc_0.eps -w 1580 -y=255 -e hp_osc_0.png
convert hp_osc_0.png -crop 1294x971+142+80 hp_osc_0_cropped.png

• Advantest R3273

  • Config printer: Config -> Copy Config -> Printer:

    

  • To print: Copy

  • To convert:

./fake_printer.py --port=/dev/ttyACM0 -t 2 -v --prefix=r3273_ -s pcl
~/tools/ghostpcl-10.0.0-linux-x86_64/gpcl6-1000-linux-x86_64 -dNOPAUSE -sOutputFile=test.png -sDEVICE=png256 -g8000x8000 -r600x600 r3273_0.pcl
convert test.png -filter point -resize 2000  test2.png
convert test2.png -crop 640x480+315+94 test3.png