Valley People 730 (ADD) Dynamap

[duosonic]

Hi,
I habe a decent looking Valley People Dynamp 730 that seems to be working ok unless you power it off. It loses any memory settings and stored programs. Also clock get‘s reset. It‘s the ADD version with Analog IOs.

There is no battery visible which Ingiessed is out of live. Does anyone know where it is located or even have a schematic?

Thanks!

PS: For Midi Manual points to a menu point 4 which doesn‘t exist. I guess the firmware is older and it‘s not configureable. Does someone have a Midi table for that one?

 

[TimG]

Here is a link to the big manual, which may have the midi table you need. No schematics it says
https://www.dropbox.com/s/r352nu4qnzz9box/Valley People - 730 DynaMap (no schematics).pdf?dl=0

The list of Valley manuals http://zine.r-massive.com/valley-people-audio-manuals/

I don’t see “memory” or “battery” in the document on a quick scan.

*Edit -the password is “preset”

 

[duosonic]

Thanks, this is the manual I already have. It describes the menu diving extensivly detailed. As I was growing up with Casio calculator watches, this somehow felt home quickly

Restoring cactory setting just wipes all. Anything I save in Banks 1 to 4 is perfectly fine, can reload etc - so maybe the factory memory was once wiped. No big deal if everything else would do. Still there needs to be a power source as it seems to be no power free memory, but that 32kB chip.

 

[TimG]

Maybe there is a big ass capacitor in there? Even that would only hold a memory for so long…

Shortwave radio guys solder supercaps into the battery compartment of their Sony ICF-2001 radios to not lose presets during battery changes.

 

[cavedata]

Check if there is a Dallas Semiconductor SRAM in it -they were used back in the day for pc motherboard cmos settings storage - they look like a standard 28 pin dip, but have a lithium battery buried in the package.

"DS1230Y/AB
2 of 13
DESCRIPTION
The DS1230 256k Nonvolatile SRAMs are 262,144-bit, fully static, nonvolatile SRAMs organized as
32,768 words by 8 bits. Each NV SRAM has a self-contained lithium energy source and control circuitry
which constantly monitors VCC for an out-of-tolerance condition. When such a condition occurs, the
lithium energy source is automatically switched on and write protection is unconditionally enabled to
prevent data corruption. DIP-package DS1230 devices can be used in place of existing 32k x 8 static
RAMs directly conforming to the popular bytewide 28-pin DIP standard. The DIP devices also match the
pinout of 28256 EEPROMs, allowing direct substitution while enhancing performance. DS1230 devices
in the Low Profile Module package are specifically designed for surface-mount applications. There is no
limit on the number of write cycles that can be executed and no additional support circuitry is required for
microprocessor interfacing."