Max7219 7-segment module FlashForth code

Max7219-based LED module driven by FlashForth

I pulled this old 7-segment display out of storage so I could write a module to control it with FlashForth. Here is the repository URL:

https://codeberg.org/infrared/ff-max7219

Using the words in max7219defs.fs and max7219cmd.fs you can control the digits, using either BCD, or controlling the segments individually. Using BCD make your programming much simpler but only gives you four letters to work with (besides the number characters).

I used individual segment control to make this simple demo which lights up each segment in sequence. Here is a video — sorry for the fuzzy image:

A demo of individual segment control

Commodore 64 FORTH: durexforth

durexforth running on VICE Commodore 64 emulator

This will be a short post, since I’ve only been playing around with durexforth for a few minutes so far. But some things I already like about durexforth:

  • Is coded for the great retro Commodore 64 PC
  • Is licensed under a free software license (MIT License)
  • Was pretty easy to build: only dependencies are make, gcc, and the ACME compiler from sourceforge. I used gcc 10.3.0 and the latest ACME SVN checkout (r319) from https://sourceforge.net/p/acme-crossass/code-0/HEAD/tree/trunk/.
  • Implements the words for the 2012 FORTH standard.

As you see in the above screenshot, you can use the % prefix to designate binary input, which is great.

Screenshot from the durexforth tutorial video

Here are the word listings:

Word list page 1

Word list page 2

I’m in the process of installing the texlive Guix package so I can try to build he durexforth PDF documentation and learn more about this FORTH. Some additional gratuitous screenshots of me playing around in durexforth:

ff-ad9833: Added Für Elise Demo

I added this tune to the demo-melodies.fs file:

Für Elise (first half) played with ff-ad9833 code

My apologies to the Beethoven fans as I had to do some violence to the tune in order to make it monophonic and to fit it inside the 3 octaves provided by my code. I also had to apply some filtering to the recording to try to remove background noise in my apartment.

Here is the tune in source code:

create furelise-p1
d_16th ne  o5 == d_16th nd# o5 == d_16th ne  o5 == d_16th nd# o5 ==
d_16th ne  o5 == d_16th nb  o5 == d_16th nd  o5 == d_16th nc  o5 == 
d_8th  na  o5 == d_16th nr  nr == d_16th nc  o4 == d_16th ne  o4 ==
d_16th na  o5 == d_8th  nb  o5 == d_16th nr  nr == d_16th ne  o4 ==
d_16th ng# o4 == d_16th nb  o5 == d_8th  nc  o5 == d_16th nr  nr ==
d_16th ne  o4 == d_16th ne  o5 == d_16th nd# o5 == d_16th ne  o5 ==
d_16th nd# o5 == d_16th ne  o5 == d_16th nb  o5 == d_16th nd  o5 ==
d_16th nc  o5 == d_8th  na  o5 == d_16th nr  nr == d_16th nc  o4 ==
d_16th ne  o4 == d_16th na  o5 == d_8th  nb  o5 == d_16th nr  nr ==
d_16th ne  o4 == d_16th nc  o5 == d_16th nb  o5 == end-score

create furelise-p2 d_quarter na o5 == end-score

create furelise-p3
d_8th  na o5 == d_16th nr nr == d_16th nb o5 == d_16th nc o5 ==
d_16th nd o5 == end-score

create furelise-p4
d_dt-8th ne  o5 == d_16th ng  o4 == d_16th nf  o5 == d_16th ne  o5 ==
d_dt-8th nd  o5 == d_16th nf  o4 == d_16th ne  o5 == d_16th nd  o5 ==
d_dt-8th nc  o5 == d_16th ne  o4 == d_16th nd  o5 == d_16th nc  o5 ==
d_16th   nb  o5 == d_16th ne  o4 == d_16th ne  o5 == d_16th ne  o4 ==
d_16th   ne  o5 == d_16th ne  o4 == d_16th ne  o5 == d_16th ne  o4 ==
d_16th   ne  o5 == d_16th ne  o5 == d_16th ne  o6 == d_16th nf# o4 ==
d_16th   ng  o4 == d_16th nd# o5 == d_16th ne  o5 == d_16th nf# o4 ==
d_16th   ng  o4 == d_16th nd# o5 == d_16th ne  o5 == d_16th nd# o5 ==
d_16th   ne  o5 == d_16th nd# o5 == d_16th ne  o5 == d_16th nb  o5 ==
d_16th   nd  o5 == d_16th nc  o5 == d_16th na  o5 == d_16th ne  o4 ==
d_16th   na  o4 == d_16th nc  o4 == d_16th ne  o4 == d_16th na  o5 ==
d_16th   nb  o5 == d_16th ne  o4 == d_16th ng# o4 == d_16th ne  o4 ==
d_16th   ng# o4 == d_16th nb  o5 == d_16th nc  o5 == d_16th ne  o4 ==
d_16th   na  o4 == d_16th ne  o4 == d_16th ne  o5 == d_16th nd# o5 ==
d_16th   ne  o5 == d_16th nd# o5 == d_16th ne  o5 == d_16th nb  o5 ==
d_16th   nd  o5 == d_16th nc  o5 == d_16th na  o5 == d_16th ne  o4 ==
d_16th   na  o4 == d_16th nc  o4 == d_16th ne  o4 == d_16th na  o5 ==
d_16th   nb  o5 == d_16th ne  o4 == d_16th ng# o4 == d_16th ne  o4 ==
d_16th   nc  o5 == d_16th nb  o5 == end-score

create furelise-p5 d_dt-quarter na o5 == end-score

That occupied 326 bytes of memory, which was the score bytes along with the bytes needed for the word headers (furelise-p1, etc.) It was divided into five parts to save memory, since some of the parts are repeated.

Free software source code and documentation are available here:

https://codeberg.org/infrared/ff-ad9833