All posts by scruss

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.

sayso-001The unit comes with no software, but has a link to https://www.dropbox.com/sh/q1q9yhahwtblb23/AACpMeXQjYyD8ZWC-65vNgcxa 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: SaySo.zip

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:

sayed1_0_003I’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).

Building the Stick of Joy

Not-even-remotely over-engineered retrogaming joystick

 

Tracking down old Atari-style joysticks is expensive, and you don’t know if you’ll get something reliable. So I built one, using Protolab‘s laser cutter.

The guts of the unit comprise:

The case is made from 6.4 mm high quality plywood, using a template generated by BoxMaker.  The external dimensions of the box are 163.05 mm x 143.05 mm x 83.05 mm, including kerf.

joystick-box

I might recommend just nabbing the top plate dimensions from the above drawing, as I made a couple of rookie mistakes in the design:

  1. I overcompensated for the laser kerf, so had to spend several hours sanding the box down to size to make it fit together. You might want to set it to zero to leave room for glue.
  2. I flipped one of the box sides to compact the cutting job. While this might’ve saved a small amount of wood, it means that the grain matches on three of the sides, but not for the fourth.

You’ll also need M4 screws to secure the joystick and stacks of washers to space the dust washer correctly. The connection is made with a couple of metres of 8-core stranded signal cable and a 9-pin female D plug. You should refer to digital joystick connector pinouts for the wiring.

Parts and materials for this joystick cost less than a used stick shipped from eBay.  It works well, and its probably the only gaming device ever to have a logo written in Akzidenz-Grotesk.