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Circuitbenders Forum => Circuitbending discussion => Topic started by: Synthetech on November 30, 2012, 07:54:19 PM

Title: PSR-12 worth bending? Tips/Tricks?
Post by: Synthetech on November 30, 2012, 07:54:19 PM
I found a Yamaha PSR-12 yesterday and wondered if this thing was really worth the effort to go in and bend.

It's my understanding that inserting switches on the data lines is the most common glitch effect bend, I just dont know what all the other known bends are for it.

Any chance on making a pitch bender on it.. or somehow make portamento work with it?
It has the YM3812 sound chip in it.. I found a datasheet on it, but it's not much info to use on bending it.  I forget what CPU is in it.. it appears to be a CPU with integrated ROM onboard it???  Not entirely sure.


I may just not fuss with it and put it up for sale.. looks like they go for around $40USD shipped on ebay.
Title: Re: PSR-12 worth bending? Tips/Tricks?
Post by: parricide on December 01, 2012, 12:48:07 PM
in my opinion, everything is worth bending :)
i couldnt give you any advice on doing it, but i can advise you to bend it because its fun!
Title: Re: PSR-12 worth bending? Tips/Tricks?
Post by: Circuitbenders on December 01, 2012, 02:09:32 PM
The YM3812 datasheet is plenty of use, for a start it tells you that pins 10,11 and 13-18 are the data line pins.

You can probably pitch it with a LTC1799, assuming it has a crystal, resonator or coil.
Title: Re: PSR-12 worth bending? Tips/Tricks?
Post by: Synthetech on December 01, 2012, 03:47:08 PM
yea, it has the same crystal as shown on your LTC1799 pitch DIY page on here.


(http://www.circuitbenders.co.uk/tutorials/crystal.jpg)

cool mod.. I might give it a go if it can be that easy to pitchbend it.
Title: Re: PSR-12 worth bending? Tips/Tricks?
Post by: Synthetech on December 01, 2012, 05:45:09 PM
Is there a simple way to create a simple sequencer/arperggiator?

Using shift registers and bilateral switches??


By jumping the keyboard matrix lines to a set of shift registers, have the input set to manual and alter the clock for speed..



or maybe use shift registers in a series/parallel arrangement..so a pattern like so can happen-

00000000      0
00000100      0
00000000      0
00000001      1
10000000      0
00000000      0
00000010      0
00000001      1

00000000      0
00000010      0
00000000      0
10000000      0
01000000      0
00000000      0
00000001      1
10000000      0

00000000      0
00000001      1
00000000      0
01000000      0
00100000      0
00000000      0
10000000      0
01000000      0



8 serial shifting registers with their end output input to all 8 lines on the matrix or send them to inputs on one shift register, then use that registers parallel output to place a note on the keyboard matrix.


have those 8 bit patterns drive a bilatteral switch that passes on the CPU's ground select signal.. I suppose you might have to use a combination of them to arrange the select signal to go from one set to the other???  I dunno.

ever heard of anything like that done?
Title: Re: PSR-12 worth bending? Tips/Tricks?
Post by: KGBgreece on January 27, 2013, 05:07:37 PM
I am a total newbie and actually made my first experiments witha wire and some stuff yesterday

but as I own an PSR-6 , I saw some dude had bent it real fine.

Not only the bending the data flow through switches, actually replacing the switches with the possibility of wiring the FM flow in different ways is reported to bring more variable results and more experimental possibilities.

Again, as a newbie, the PSR-6 is a pain in the pass to disassemble, but in my newb eyes its board seems pretty easy to work with , f.e. making the data flow bending.

this is the best sample I found

Circuit Bent PSR-6 (http://www.youtube.com/watch?v=5qWK2G4l5OE#ws)

Title: Re: PSR-12 worth bending? Tips/Tricks?
Post by: iwillbeacircuitbender on June 07, 2015, 01:07:51 PM
No, this keyboard uses the YM2413 sound chip. Nowhere does it have an OPL2