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polysix retrofit?


kokoon
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hi guys.

i'm getting a korg polysix and seeing it doesn't have a CV and GATE in - well i'm researching options to interface it somehow. i've found an interesting diy retrofit here http://www.angelfire.com/geek/srlabs/p6retro.html

it utilizes a PIC16F84 and apparently it connects on the keyboard bus. i immediately thought about using a CORE and a DOUT module... ofcourse i could just make the kit as is described on the said page but i have no means of PCB production and also burning a 16x PIC would be hard...

anyone?

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Hi Kokoon,

you could ask the guy to assemble the source code for the PIC18F452, it's nearly source-code compatible. He only needs to change the baudrate settings.

You could also use the bootstrap loader to upload the code like you would do it with MIOS. It's only important that the program starts with two "goto"'s to the start label (the first one will be overwritten by the BSL)

Best Regards, Thorsten.

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that's great! i've sent him a mail.

still, driving the synth directly from 1 CORE and 1 DOUT (or maybe AOUT?) would be really nice... that would really be a cheap polysix retrofit! the keyboard bus is 16 lines and the only question is how to mux the notes. and i'm sure i can find the info about this on the net. now if only there'd already be a midibox retrofit for some other keyboard matrix synth... you know of any?

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that's great! i've sent him a mail.

still, driving the synth directly from 1 CORE and 1 DOUT (or maybe AOUT?) would be really nice... that would really be a cheap polysix retrofit! the keyboard bus is 16 lines and the only question is how to mux the notes. and i'm sure i can find the info about this on the net. now if only there'd already be a midibox retrofit for some other keyboard matrix synth... you know of any?

Are you looking for something like these found in the MIOS Download area?

sm_example1_v2.zip  41k 

How to drive a button matrix of 8x8 = 64 buttons. See also this connection diagram. Additional examples, e.g. for 1024 buttons scanned by a single core module, are planned once this driver has been tested in a real environment.

sm_example2_v1.zip 43k How to handle a button matrix of 8x8 = 64 buttons superfast (within 80 uS) and with debouncing.

I've done some further development of those examples but I haven't yet expanded beyond an 8x8 matrix.

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i don't need scanning (DEmuxing) the matrix but muxing the midi note events onto the existing keyboard bus. i just need mini-in for the machine. i'll try to dig out the keyboard bus signals specification cause ATM i've actually no idea what exactly it looks like.  ;)

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  • 3 months later...

okay i've done some researching and have come to the following:

- the processor scans the keyboard like this: each cycle it outputs high to each of the 8 lines and scans the 8 other lines for status of keys.

- this could probably be simply implemented on midibox platform.

- is there any way to get 8 inputs and 8 outputs on just the CORE module? i mean without an additional DIN and DOUT?

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okay i've done some researching and have come to the following:

- the processor scans the keyboard like this: each cycle it outputs high to each of the 8 lines and scans the 8 other lines for status of keys.

- this could probably be simply implemented on midibox platform.

- is there any way to get 8 inputs and 8 outputs on just the CORE module? i mean without an additional DIN and DOUT?

That's an 8x8 scanning matrix... Maybe you could do the reverse of the code down there to drive it...

The 8 lines that go high connect to a DIN, and the 8 lines it scans go to a DOUT. When one of the DIN lines goes high, you can tell that the polysix is scanning that set of 8 keys, so then drive the DOUT pins so that they go high depending on the MIDI Note # received at the MIDI In.

Question is, how fast does the polysix scan, and will the PIC keep up?

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is there any way to get 8 inputs and 8 outputs on just the CORE module? i mean without additional DIN and DOUT?

You could use the 8 pins of J5 as digital inputs (see j5_din example), and the 8 data pins of the LCD port as digital outputs

Best Regards, Thorsten.

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You could use the 8 pins of J5 as digital inputs (see j5_din example), and the 8 data pins of the LCD port as digital outputs

Best Regards, Thorsten.

that's EXACTLY what i wanted to hear! fantastic! i'll go and make this now. see you in xx months :)

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