Real PDP-8/I, left. My PiDP-8/I, right.
(PDP-8/I photo from here.)

Building and Using the PiDP8/I

After attending the Vintage Computer Festival - East in April 2017 I learned about Oscar Vermeulen's PDP-8/I re-creation. Please visit his web site if you haven't already. It's a fun and worthwhile trip back in time to build and enjoy your own DEC PDP-8/I. The three major steps: build, install, use!

1. Build. Photos of my build show the process I went through to get my shiny, new 1968 computer up and running. Best of all, it doesn't cost the original $12,800 in 1968 dollars. :-)

2. Install. Tangentsoft.com provides the software. Simply copy the image to an SD card and insert it in the R-Pi.

3. Use. This rest of this page focuses on a few things related to using it rather than the nuts and bolts of the system.

Unique Things Here

Here are a handful of things I've enjoyed playing with in OS/8.

• TECO, the incredible editor and language. You can't create and change files if you can't use an editor. You need to learn TECO's basics to truly travel back to 1968. This manual is from 1978, the one I first used, so will likely have some differences, but it does have special OS/8 sections. I reformatted it using LaTeX. (More teco links at my PiDP-11/70 page.) What does it stand for?

  Tremendously Extensible Code Organizer?
  Typing Everything Creates Output?
  Tough Editor Causing Obsession?
  

  No, it is... Tape/Text Editor and COrrector!

• UW FOCAL (FOrmula CALculator). I used LaTeX to present the unaltered original text and did my best to match font, size and spacing for a pristine copy. Please let me know if you spot errors. The version on OS/8 does not include all commands in this manual. See the tangentsoft web site for details on differences.

• Despite adventure being written in 1977, the OS/8 image comes with a version retrofitted for the 1968 OS. Be sure to check out my adventure page where the "Maps" section will be helpful. My maps are generated from the original set up file and fully enumerate verbs for movement between rooms.

• Run some actual 1968 scientific code. (After untarring, see the README.) Much of my career has been in radar and RF communications. An extraordinarily successful RF propagation model is the Longley-Rice Irregular Terrain Model, still in heavy use worldwide.

  I corrected Fortran-IV OCR errors in code taken from the 1968 report. It was written for the CDC 3600 computer. Steve Tockey broke it into one file per subroutine and modified syntax as necessary for the OS/8 F4 compiler. For old times' sake, I used TECO to create the .f4 files, but you can use tools like os8-cp. Steve made two batch files, one to compile and one to run the program. You can use those or type the commands yourself.

  Anita Longley named her program COMTE and I'm unsure what it means, maybe COMpute Terrain Effects? Here is output, some quite different from Longley's, but the CDC 3600 used a 48 bit word length and floating point representation compared to the PDP-8's 12-bits.