Patches and discussion for Ensoniq VFX family

On Tue, Mar 28, 2017 at 01:41:19AM +0000, wjwilcox@... [Ensoniq-VFX-SD] wrote:
> A replacement 68HC11A1P keybed microcontroller arrived today and was installed.  Unfortunately, it did not solve the problem.  On the bright side, I didn't make anything worse....

This makes sense to me.  If my understanding of the way the keyboard
functions is correct (the distance between the coils on the board and
the metal pieces in the keys is measured, somewhat similar to a metal
detector, distance X is key up, smaller distance Y is key down, and
even smaller distance Z means pushed into aftertouch zone), the
processor being able to figure out that a key is pressed but not be
able to figure out whether it should or should not be considered to be
in the aftertouch zone would be an odd thing, considering the digital
function of the processor itself.

Have you read Ensoniq Service Builletin 12?  It gives a lot of
keyboard information.  They describe four KPC versions and different
coil board types.  I find this note in there: "Remember that a KPC
board can only be replaced with the whole keyboard assembly as it
contains information specific to its particular coil boards and keys
in its memory."  I cannot decide if the note means they just know
which style coil board is attached, or if there was some factory
calibration proceedure that stored information for the particular
keyboard and analog parts on the coil boards.

I read the datasheet for the 68HC11A1P, it has 512 bytes of EEPROM.
That may have stored callibration information.

I wish there was a complete schematic of the keyboard somewhere.  The
one I can find on the web is missing a page or two.  But I probably
wouldn't be able to understand it without someone to explain it to me
anyway.

Since the problem seems to be common to all the keys, a guy might look
at the schematic and examine any analog components that seem to be
common to all keys, and check to see if they've drifted far out of
spec (perhaps zapped by the power surge you described).  

You said you had an aquaintance who was a former Ensoniq engineer?
That's probably a better resource than anyone here, certainly better
than myself.

But, at this point I fear you may be looking at a keyboard transplant,
or a Frankensoniq built from yours and another donor. :-(

--> Steve

-- 
Steve Wahl    steve@...

Real men don't take backups, they just "mv home.tar.gz
olsen_twins_hottub.mpg" and share it on KaZaA  -- Unknown