stepleton/hpgl2tek

For making graphics and animations on Tektronix storage tube systems

hpgl2tek: For making graphics and animations on Tektronix storage tube systems

This repository contains a collection of Python programs useful for displaying vector graphics on Tektronix 4010-series terminals and on 4050-series computers with the R12 "fast graphics" ROM expansion. One program facilitates the creation of old-fashioned frame-by-frame animations composed of many individual vector graphics frames (which you must film with a camera pointed at the screen). For further documentation and information about software dependencies, please see comments within the programs, which are these:

hpgl2tek.py

Converts HPGL files for display on some old Tektronix computers and terminals. This program can compose multiple HPGL files into a single output file after scaling and transforming their contents in various ways. All of this same functionality is available to other programs when this file is used as a module.

text.py

Creates HPGL files that contain text rendered in Hershey fonts. The Hershey fonts are free rudimentary vector fonts made by the U.S. Navy in 1967 for use with vector CRT displays. They're still useful in that application, and they're also useful for plotters.

animate.py

Creates animations for rendering on suitably-equipped Tektronix computers. Reads in a file that uses a hastily-cobbled language to describe a multi-frame vector graphics animation via compositions of lines and moving HPGL file elements. Output may go to an MP4 file for viewing on a modern computer or to a ZIP file containing files that can be used by a Tektronix 4050-series computer with the R12 "fast graphics" ROM pack. (The files must be placed on a tape cartridge or the McGraw 4050 Flash Drive tape drive emulator.)

zipchopper.py

Chop up an animation ZIP archive to something Flash-drive compatible. The 4050 Flash Drive is an extremely useful device, but it seems like it may have issues handling file numbers greater than 250 or so. (Or this could be the Tek instead.) Some ZIP files have animations with more frames than that, so this file breaks those down into separate zip files that have been renumbered, counting up from 1. No ZIP file will have more than 226 files inside of it.

slidesho

Utilities for displaying a slideshow of vector graphics files on a Tektronix 4010-series terminal (including the 4006-1) attached to certain configurations of the RC2014 kit computer.

Demo

The included Makefile exercises hpgl2tek.py and text.py to generate a vector graphic suitable for rendering on a Tektronix 4010-compatible terminal. On a modern Unix-alike, you can experience it by opening up an xterm in Tektronix mode (xterm -t -fg green) and typing make show.

Nobody owns hpgl2tek

This collection of utility programs, software libraries, and documentation distributed alongside them are released into the public domain without any warranty. See the LICENSE file for details.

Acknowledgements

It would not have been possible for me to write this software without the help of the following people and resources:

• bitsavers.org's archived technical documentation.
• Monty McGraw's archived Tektronix 4050-series programs and technical documentation.
• The "Flash Drive" Tektronix 4924 tape drive emulator [1], [2], [3] by Monty McGraw and John (?).
• J.L. for allowing me to borrow a Tektronix 4054A with Option 30!

-- Tom Stepleton, 22 May 2024, London