Korg Poly800/EX800 Users

I would recommend that you use a simple reset circuit to hold the two flip flops in the dormant state for a second after power up.

A simple resistor and capacitor fed into one of the 74HC14 gates will provide a delayed reset. Feed the output into the clr on the flip flops.

I don't really want to change the boot code; especially when you have two spare gates on the 74HC14 to use for a power on delay circuit.


The boot ROM can't be written to when it is in the boot socket. So there's no chance of it being corrupted - ever, while it's in the boot socket location.


Mike



________________________________
 From: bimmerfan222 <bperkins211@...>
To: korgpolyex@yahoogroups.com 
Sent: Sunday, September 16, 2012 5:52 PM
Subject: [korgpolyex] Re: Data Dial Encoder Project - WORKING!!!
 

  


--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
>
> You could use the two spare schmitt triggers in the 74HC14. By the way, you should use HC series, not LS.
> 
> Mike

I guess I'm at a disadvantage at how to use the schmitt triggers to accomplish this.  Any pointers?

The LS package was the only one I had in my TTL/CMOS stash.   I'll get some HC's in my next part's order.

--- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote:
>
> I could change the boot code for you. Such as, hold down Bank Hold and then Up or Down to engage the clear function.
> 
> Easy to do. 

That would be the better version in my opinion.  That way I can retain my "jogwheel" feature. 
I'm guessing it's wise to keep the CLEAR function in the event a corrupt code bricks the Korg up?

Is the 1.5b kit you sent me able to reflash the Boot Rom?  Is it wise for me to get an extra Chip so I can make a backup Boot Rom?
If I somehow compromise my only boot code while poking and prodding into the synth, I'm SOL until I get another chip.

-Blaine