Decoding MIDI with discrete logic

Dave Halliday dave.halliday at
Fri Apr 30 08:15:42 CEST 1999

>     From: WeAreAs1 at
>     To: synth-diy at
>     Date: Thu, 29 Apr 1999 19:36:51 EDT
>     Subject: Decoding MIDI with discrete logic
>     Hello list,
>     I have a need for a couple of boxes that will decode a simple MIDI 
>     message and output a high or low logic signal.  I have absolutely no 
>     software programming skills, so I cannot use a microprocessor or PIC 
>     device to do this, even though that might be the most efficient method.
>     The MIDI message would be a continuous controller (the controller 
>     number is as yet to be determined - probably one of the less often 
>     used ones).  I want the logic gate output to go high, and stay high, 
>     whenever this particular controller is received with a value of 64 or 
>     higher.  If the decoder circuit receives that same controller with a 
>     value of 63 or lower, the logic output would then go low, and stay low.

Question here is do you need just one of these or will you need 
several.  If you need several, it might be better to get a pre-made 
CPU based solution and spend your DIY efforts on getting all of the 
peripherals to work.

Doing this in discrete logic will not be a simple task.

I would check out http:\\ - spend some time drilling down 
into their website and you will find PC boards, pre-programmed CPU 
chips and full details on building your own device with their parts.  
Looks flexible and they make good stuff...

You would have to buy a PC board ( entirely optional ) and the 
pre-programmed CPU ( not optional ) - they have the schematic diagrams 
available so you can go as much DIY as you want.

Figure that you may spend $60 but you would not have to deal with 100+ 
TTL chips, several amps of +5 and you know that it would work from the 

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