roland 181, 182, 184 analog controller keyboard

[WeAreAs1 at aol.com]

In a message dated 5/10/00 5:58:10 PM, you wrote:

<<anyone have the schematics on these puppies?>>

It would appear, judging by your earlier message, that you are in the process 
of building a CV controller keyboard.  In this case, the schematics for the 
top-of-the-line model 184 will not likely do you much good, since it uses a 
custom-programmed MPU chip that is no longer available from Roland.  This 
chip scans the keyboard matrix and sends the proper bytes to a simple DAC, 
from which the CV is then multiplexed to four different CV outputs.  The MPU 
has its ROM built in, and I'm not sure there would be any way of downloading 
the internal ROM contents (for copying into an EPROM).  

If anyone knows a method for doing such a thing, I would like to hear how it 
would be done.  Then, for instance, we could clone a bunch of obsolete Roland 
and Korg MPU's, at least for the purpose of keeping some of those classics 
running, if not for the purpose of building our own new ones from scratch.  
Some other models that have such internal ROM MPU's are:  TB303, TR606, 
TR808, Jupiter 4, Korg Poly 6, Mono/Poly, Trident MkII, etc.

Getting back to the 181/182/184 keyboards, you'll be able to build a copy of 
the 181 or 182, since they use garden-variety parts that you can still buy.  
No 4-voice polyphony and arpeggiator, though...

Michael Bacich