Work-in-progress: Sayso Globord audio decoding

You may still be able to get surplus Sayso Globord programmable LED signs in surplus stores. It’s a 7×24 LED scrolling sign that you can program with a lightpen or with audio input.


The unit comes with no software, but has a link to printed on the box. It’s an archive of the programming software, manual, and canned audio files for a whole bunch of standard messages. Here’s an archive if the dropbox link goes away:

The audio files used for programming the display are clearly FSK-encoded, but I haven’t quite worked out the relationship between the tones and the display bits. Here’s what I’ve worked out so far:

  • Files are made up of 12 audio blocks, each about 0.9 seconds long. Each block appears to correspond to one 7×24 display screen.
  • Mark (1 bit): Three cycles, 96 samples at 44100 Hz: 1378.125 Hz
  • Space (0 bit): Four cycles, 256 samples at 44100 Hz: 689.0625 Hz

The editor runs nicely under DOSBox, so you can experiment and save samples as WAV files. Here’s a sample display with its corresponding audio linked underneath:


I’m not sure how much extra work I have time or inclination to put in on getting this working, but I hope that my preliminary work will be useful to someone (maybe this person).


  1. Thanks for posting this. I found one of these sort of retro signs and wondered if I would be able to program it. With an ausio input I had my doubts that I would find the necessary tools. BTW The still have some at KW Surplus in Kitchener Ontario for $6.99.

  2. Hi Pete – I didn’t get any further than looking at the FSK output. The sticking point was that the Sayso needed to be reset to display a new message. It wouldn’t be impossible to hack up a remote reset switch, but it was too much work for me.

    Please don’t give me another good reason to go to K-W surplus …

  3. So, I was cleaning my office up to move, found this LED display I got when I was a kid in a yard sale for like $2, and thought “there’s no way someone still has the tool to do this.” but here you are you mad lad. Thank you so much. runs like a dream in DOSBOX.

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