PDP-1 music creation tools

Here is a zip file containing a bunch of tools that let you create music for the PDP-1 minicomputer. It converts text files containing music data in the PDP-1 Harmony Compiler format to midi files that can be played on a PC. Without this tool, the only way to listen to music written for the PDP-1 is to punch a paper tape of data, and play it on a PDP-1. Now, anyone can write and debug music for the PDP-1 from the comfort of their home. Check out the README file inside the zip for details on how to do it.


Here's a midi file generated by these tools. It's the 3rd movement of Bach's Organ Concerto in G. Of course, the sound quality varies with the quality of the midi synth used to play it, but that's not the most important thing. The goal is not to make great midi music files, but to accurately reproduce the notes contained in a Harmony Compiler input file to enable debugging of the music files on a modern computer.


Once you've written and debugged some music for the PDP-1, you no doubt want to actually hear it played on the PDP-1. The zip file below contains the simh simulator, and the Harmony Compiler phase one program to compile a music text file into a binary intermediate format. The resulting binary file is then punched onto paper tape, and loaded into the PDP-1 to play. Check out the README file inside the zip for details on how to use it.

Note: The docs are still being written on how to use this, but if you're brave (or I've personally told you how to use it) here's the link.


If you've made new music for the PDP-1, I'd love to hear from you. You can contact me here:
   pdp1_hc *at* scrapheap.net.
If you send me the text input file (and the binary file too!) I'll play them on the PDP-1. The eventual goal is to record the PDP-1 playing pieces that people develop, and post the recordings on this website, but that is not functional yet. Check back soon though!

Not sure what to transcribe for the PDP-1? Here are a few suggestions:
     Flight of the Bumblebee
     Various 2 and 3 part Inventions by Bach.
         We already have 2 part inventions numbers 1 and 13, but we want more.
     Some Scott Joplin rags. My favorites are:
         "Maple Leaf Rag" (though there are many high notes the PDP-1 can't play. Perhaps transpose down 8 half steps?
         "Elite Syncopations"
         "Peacherine Rag"
         "The Entertainer (probably need to transpose down 4 half steps)
         "The Strenuous Life (probably need to transpose down 5 half steps)
         "The Easy Winners" (recently transcribed!)
         "Solace" (work in progress!)
     Baroque Hoedown (from Disney's Electrical Main Street Parade)
     Take 5
     Pink Panther Theme
     Baby Elephant Walk
     Screamer (circus music)

In addition to the files in the zip above, you may need some additional tools. If you're running Linux or Unix, you probably have perl on your system. If not, get it. If you're running Windows, you can get ActiveState Perl for free. Go here to get it:

ActiveState Perl

Hint, you want the "AS Package" for Windows (x86).

If you're on MS Windodws, you'll want a bash shell interpreter. You don't technically _NEED_ one, but if you don't have it, you can't run the scripts that automate various tasks. You'll have to do them by hand, or write your own batch files. Do yourself a favor, and make sure you have a shell interpreter. The scripts were developed using the MKS toolkit, which is not free. However, they should work just fine under Cygwin. You can get Cygwin here:

Cygwin home page

Hint, click the "Install Cygwin Now" button in the upper right corner. The default install includes bash.

Simh version 3.6-1 is included in the hc_binmaker.zip file above. It works great. However, if you want a newer version, you can get it here.


The zip file includes version 2.38 of midge, and I know it works with hc2midge, but if you want a newer version (2.41 is available as of this writing) you can get the latest version here: