Yamaha CS80

This is what you get when a team of organ engineers use their key 
assigner logic for a synthesizer. ;)  On the EX-2 each manual can sound 
7 voices each, but together they can only sound 11.  They use the same 
ring memory table in the GX-1 and key assigner of the CS 50/60/80.  
There is a somewhat cryptic explanation in the CS service guide, pages 
11 to 19, describing the encoder for 4 voices.  JH references the 
service guide on his CS50 page,

http://home.debitel.net/user/jhaible/jh_cs50.html

  If you look closely you'll see the actual electrical operation of the 
key scanner is ternary, not binary, it uses both -6.5v to 0 and 0 to 
+8.5v to derive logic states.

Crow
/**/

Colin f wrote:
> The GX has all its voice cards in 80 pin 0.1" card edge sockets, so swapping
> round a bad card is simple.
>  
>   
>> I'd be interested to find that out too.
>> The GX is odd. I assume it keeps a list of free voices in least recently
>> used order, assigns the voice at the head of the list to a new note and
>> sends that voice to the end of the list when it is released.
>> After an initial clear, for a repeated single note, it starts at voice 2,
>> then cycles thru 3,4,5,6,7,1, back to 2...
>> If you play an overlapping note before the first cycle thru 7 has complete,
>> it plays the second note on the next voice.
>> But once thru the cycle of 7, a second note will always be on voice 8.
>> That suggests to me that the intial state of the LRU list is
>> 2,3,4,5,6,7,8,1.
>> Once you go through the first cycle, it skips voice 8, leaving 8 at the head
>> of the LRU, where it stays until at least two notes are overlapped.
>> One particularly odd thing is that if voice 8 has been brought in during a
>> cycle of single notes, on release it seems to put both voices 8 and 7 at the
>> end of the LRU list, so voice 7 is not used as soon as you'd expect.
>> As you might imagine, mimicking this behaviour precisely in software is
>> going to be a fun job.
>>
>> Cheers,
>> Colin f
>>
>>
>>
>>
>> ------------------------------------
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