Little Sound DJ
DIY MIDI Interface

Rolemodel told me that the commercial MIDI interface for his phatt GameBoy music software Little Sound DJ was no longer available. So, I offered to design another for him. The interface has a MIDI socket coming in, and connects to the GameBoy's gamelink port.

The original interface is able to accept any MIDI data and filters out only the special MIDI clock signals to syncronise LSdj. However, it uses a custom programmed chip, which is bad for home constructors.

The interface I designed uses only simple parts which are easy to buy (just 3 chips, 3 resistors and 2 capacitors). On the other hand the DIY interface assumes that the incoming MIDI data is made of only clock signals. Other MIDI signals are also interpreted as a clock signals - so if other signals happen over time LSdj would speed up.

It is possible to build the circuit into a very small space, and it is powered by the GameBoy so no external power source is required:

The completed interface looks like this

The information on this page should be enough for someone knowing a little about electronics to build the interface. If you need help just send me an email - the address is at the bottom of the page.


Also see my LSdj Pitch Control! HERE


Gamelink cables
To connect between the circuit and the GameBoy you will have to modify a gamelink cable. These are available in most computer games stores, but you need to watch out for some things:
I needed to use an adapter to get all 6 gamelink connections working

How to use
  1. Connect a MIDI clock source to your new MIDI interface, and then connect to your GameBoy's gamelink port (with the GameBoy switched off).
  2. Power up LSdj and make music!
  3. When you want MIDI syncronisation go to the 'Project' screen. If you just turned on the GameBoy and you are still in the 'Song' screen, you can do this by pressing 'select+up'
  4. Scroll down to the line starting with 'Sync', which normally has 'off' next to it.
  5. Press 'a+right' until 'MIDI' is displayed.
  6. Now go back to the song screen by pressing 'select+down'
  7. Press 'start'. If there are MIDI signals coming into the interface then LSdj will start playing in time to them!! If there are no incoming MIDI signals then LSdj says 'wait' on the info line - when MIDI signals arrive this will change to 'sync'.
GameBoy + interface + MIDI clock source

Here are some hints:

All this info is provided totally free, but of course remains my copyright. Any application of this information is at your own risk - if any harm comes your GameBoy, yourself, your LSdj cartridge, your studio gear, or in anything else then it is not our fault.

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(c) Gareth Morris 2002
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