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Subject: RE: [korgpolyex] Re: Two different retrofit kit

From: "Jose Curvo" <homem_eletronico@...>
Date: 2007-04-13

88 note range? I will check the progress page more often. Never thought of
that. It's a great feature!


>From: "korgpolyex800" <korgpolyex800@...>
>Reply-To: korgpolyex@yahoogroups.com
>To: korgpolyex@yahoogroups.com
>Subject: [korgpolyex] Re: Two different retrofit kit
>Date: Thu, 12 Apr 2007 18:56:15 -0000
>
>Hi Kokoon,
>
>I miss my SH-101 for just that reason.
>
>I spent some time thinking about how to do, as you so appropriately
>put it, "decent portamento". At one point I was looking at using the
>existing master DCO bend circuit to create the portamento but I fear
>that might not give us a "decent" portamento and I just know it's
>going take a lot of programming time to make it work. Another way to
>do portamento would be to build a brand new master DCO that was able
>to sweep across the entire 88 note keyboard (did I mention that I'm
>going to provide full 88 key range as an selectable parameter?). But
>such a master DCO will require even more circuitry so it will
>definitely have to go into the full retrofit kit. I may try to use the
>bend circuit first and see what sort of results I get, if they are
>"decent" then perhaps we can avoid adding more hardware.
>
>Isn't this fun!
>
>Mike.
>
>--- In korgpolyex@yahoogroups.com, "jure zitnik" <kokoon@...> wrote:
> >
> > all i'm interested in is a decent mono mode with portamento :)
> >
> > cheers,
> > kokoon
> >
> > On 4/12/07, korgpolyex800 <korgpolyex800@...> wrote:
> > >
> > > Hi all,
> > >
> > > Well, if there's one thing I've learned it's that you should never use
> > > polls to make decisions because you can be sure that poll questions
> > > were written and scripted by an idiot.
> > >
> > > OK, down to business.
> > >
> > > After looking at the poll results and seeing some of the responses I
> > > was prompted to rethink the goals of the project. Taking into
> > > consideration all of the work I've done so far and the progress made
> > > it would be possible to take all of the new sysex functions (and more)
> > > and put them into ROM space if we could add just one additional 8K
> > > ROM. The challenge is to add that ROM without requiring major surgery
> > > on the hardware. Well it turns out that a small board that would use
> > > two 8K ROM's and one XOR logic gate chip could be made that would map
> > > the second ROM into the same address space as the existing RAM. The
> > > second ROM would be disabled for the low 2K of address space where the
> > > 2K RAM exists. This would mean that we would end up with 14K or ROM
> > > instead of the existing 8K. The only problem with this concept is that
> > > we don't get any additional RAM at all. This would mean that any new
> > > sysex commands would have to be wedged into the existing RAM in such
> > > as way as to not stomp all over the existing programming. I'll have to
> > > do some testing to see what scratch RAM is available in that little 2K
> > > RAM chip.
> > >
> > > Then, there is the big retrofit project. This will give us so much
> > > additional RAM, ROM and other hardware that we'll be able to transform
> > > the Poly 800 and EX800 into something much more than we could ever
> > > have imagined. It requires removing one IC and adding a much larger
> > > plug in board. It will include two flash EEPROM's which means we'll be
> > > able to download new code as it becomes available. And it will have
> > > many new performance parameters and operational capabilities.
> > >
> > > I think perhaps I should go for the easier retrofit kit first and go
> > > from there.
> > >
> > > Mike.
> > >
> > >
> > >
> >
>
>

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