Decoding MIDI with discrete logic

[Jeremy Brookes]

> It might appear that all that has to be done is to
> turn the 8 bit serial lumps into parallel & see what is there, but
> WARNING WARNING you have to account for thigs like , what if there
> is some sysex coming down, you have to know not to look at this,
> there could be anything there.

There shouldn't be a problem with sysex as all the bytes inside a sysex
message are 7Fhex or less, while the byte for the controller info is 80hex
or above (can't remember exactly). So if the logic is matching for the
controller byte, it can't get confused by a sysex byte. MIDI is actually
quite well written at byte level when you look into it closely enough. It
appears to have been written to accommodate very simple processors or even
logic chip processing.

jezz.

------------------------------------
   jezz at bluebear.freeserve.co.uk
http://www.bluebear.freeserve.co.uk
   MIDI, SYNTHS, CIRCUITS, STUFF