[sdiy] keyboard hardware producers?

[rsdio at audiobanshee.com]

It's certainly possible to reprogram vintage hardware, even the stuff that's older than Flash. Every synth with presets, and even some with just a digital keyboard, have MCU chips with code in EEPROM. Nearly always, those EEPROM chips are socketed. Thus, they can be removed and reprogrammed without a debug connector. You do need to be very familiar with the MCU in order to reprogram it on a unit that doesn't have debugging hardware on board. You'd be surprised how many famous synthesizers are based on standard micro controllers.

Newer MCU designs moved the EEPROM to Flash, and subsumed the external chip to an internal feature. Thus, even without the socketed EEPROM, there is probably a way to reprogram. It's really the same story for everything from vintage to modern. Unless there's no digital component at all, it can be reprogrammed.

The challenge is to determine how all of the custom hardware attached to the MCU functions. I've been able to reprogram the Roland PG-300 to handle generic Continuous Controller messages, and others have famously upgraded Roland synths as well as Oberheim and others. But these things don't come with documentation beyond what you see in the schematics and service manuals.

Brian Willoughby
Sound Consulting


On Dec 28, 2014, at 8:07 AM, MTG <grant at musictechnologiesgroup.com> wrote:
> Terry, you mean reprogram or refit a CPU board of your own?
> 
> I've always wondered what kinds of things have flash microcontrollers with accessible debug connectors that we could repurpose or upgrade. I used to use old modems as general purpose micros at one point. They would have CPU/EPROM/RAM/Uart of course. Nowadays it would be even easier with something containing a standard microcontroller.  I looked into doing this with a PTX camera controller.
> 
> GB
> 
> On 12/27/2014 7:31 AM, Terry Shultz wrote:
>> I tend to not want to build Keyboard systems as it is cheaper to buy M-Audio Controllers and write software to add my features.
>> 
>> Just a thought anyway.
>> 
>> best regards and Happy New Year,
>> 
>> Terry Shultz
>