simple PAIA keyboard scanner/arpeggiator (was Re: [sdiy] trying to understand appregiators in late 70's synths)

[Dave Manley]

Dan Snazelle wrote:
> i would love to have access to these pages!!
> 
> 
> 
> Digging through the files, this arpeggiator option is described in 
> Simonton's 'Friendly Stories about Computers/Synthesizers' on pages 
> 8-13.
> 
> --------------------------------------------
> check out various dan music at:
> 
> http://www.myspace.com/lossnyc  
> 
> 
> http://www.soundclick.com/lossnyc.htm
> 
> 
> http://www.indie911.com/dan-snazelle
> (or for techno) http://www.myspace.com/snazelle 
> 
> 
> 
> 
>> Date: Thu, 8 Jan 2009 21:24:40 -0800
>> From: dlmanley at sonic.net
>> CC: synth-diy at dropmix.xs4all.nl
>> Subject: simple PAIA keyboard scanner/arpeggiator (was Re: [sdiy] trying to	understand appregiators in  late 70's synths)
>>
>> Dave Manley wrote:
>>> Florian Anwander wrote:
>>>> Hi Dan
>>>>
>>>>> forgive for being an idiot, but how can i incorporate this into an 
>>>>> arppregiator?
>>>> Yep. your doubts aren't wrong. This keyboard is only the first step, but
>>>> it delivers a key as digital 6-bit word. This has to be 'postproduced'
>>>> somehow.
>>>>
>>>>> due to my lack of german...is it a mono keyboard?
>>>> Hmm, yes and no. If you'd put a D/A direct behind the Latch then it
>>>> would be monophonic and would always send the highest note.
>>>>
>>>> But one might add further logic to make it polyphonic and need this for
>>>> the arpeggiator too. I am only brainstorming (as far as there is any
>>>> brain to storm inside my old head ;-)) to the mail client now...: e.g.
>>>> for eight voices you need eight latches. The trigger from the 4051 must
>>>> be advanced with each new pressed note to the next latch. But then I am
>>>> not sure how to act on, if more than eight keys are pressed.
>>>>
>>> Years and years ago, there was a Paia keyboard scanner circuit that 
>>> you could use as a simple arpeggiator (IIRC) by controlling the scan 
>>> clock. Normally, the scan clock was running so the entire keyboard was 
>>> being scanned every ~1 ms.  In this mode the scan clock was stopped 
>>> when a depressed key was found, and then re-enabled based on the 
>>> arppegiator rate.  As it scanned the keyboard from low to high, it 
>>> would output the digital code for each currently depressed key, pause, 
>>> and then go to the next key.  It looks like the elektor circuit could 
>>> probably do the same with some mods.  If you get a little clever, you 
>>> could probably change the direction of scanning for up or down 
>>> arpeggios (and if really clever up/down or random).  I think this was 
>>> described in one of John Simonton's lab notes when he started 
>>> introducing the digital keyboard/computer/quash/etc.
>>>
>>> -Dave
>>>
>>>
>> Digging through the files, this arpeggiator option is described in 
>> Simonton's 'Friendly Stories about Computers/Synthesizers' on pages 
>> 8-13.  These were scanned by Anders Sponton, and at some point I grabbed 
>> a copy.  I can't find them with "The Google" - does anyone have a link?  
>> If not, and someone is interested I can make them available.
>>
>> BTW, the pause circuit is even simpler than a 555. It is an RC.
>>
>> -Dave

Here's a link:

http://home.comcast.net/~polyphony/docs/ek3.pdf

Not the whole 'Friendly Stories' but the part about the keyboard scanner.

-Dave