[sdiy] Polyphonic keyboard scanner

[thx1138]

On 8/2/09 9:58 AM, "David G. Dixon" <dixon at interchange.ubc.ca> wrote:

>> I will have the boxes brought out so I can look for them. I know I don't
>> have them in electronic readable form. Just hard copy.
> 
> Terry, I found the schematics (in the form of the service manual) for OB-Xa
> here:
> 
> http://www.lazyblueoctopus.com/html/oberheim.html
> 
> One glance at these was enough to convince me that a microcontroller is the
> way to go!  Does the circuit really need to be that complicated to do what
> it needs to do?
> 
Hi David,

The Z-80 was used for Keyboard scan, Front Panel control, Auto-Tune etc.

The E-Mu 4060 keyboard was about the simplist incarnation from that time
point.

The 4060 was a 16 voice Gate and CV based system. Later on we added a disk
drive and extended memory card to the the system.

Simple programs were loaded via Cassette using a Kansas City Style loader
from a cassette deck.

The keyboard could be split and it was a true polyphonic sequencer
controller.

I still have mine in the flight case in the Garage.

We never published the schematics for this design but I have the complete
archive here in my Lab. The software listing is on a printout in a box under
my work bench I think.

So much history is hidden with the dust and spiders in my garage I fear.

Where are you based at? I am in the Los Angeles area if you wish to explore
some of this history.

Regards,

Terry