Casio Sequencer

[computer at sea]

Hi all,

Long time no see.  I wanted to drop by and give a heads up on a circuit that I'm working on.  It's a sequencer for SK series casios, though I've tested it with a few MT's as well.  I suspect the bottom end of the keyboard matrix is probably the same on all the casios of a certain vintage.

I'm using a 40106 to create a clock signal (then another couple pins there to invert it), a 4040 to have the option of dividing the signal, and a 4017 to create the actual sequence.  Here's a link to a video of an early prototype working with a sk-5.  Sharp observers will also recognize Graham's Slo-AD mod in there.
https://drive.google.com/open?id=0B9i2z8eh5tj0MGVmT3NweldKdm8


In this version there are relays, rather than 4066's, which are what I have now.  They connect to the keyboard matrix  Once I get it off the breadboard, the plan is to have a patch bay, so you can patch any note into each of the eight steps. Also, you can use the outs of the 4040 to send divisions of the clock signal to anything you can find that is triggered by 5V.  I've had luck running it to speak and spells and to LFO's in other circuits.  The schematic below is a rough sketch off the top of my head, as I am at work right now, but I think it's correct.

[computer at sea]

Here's an improved version of the sequencer circuit that can count up, down, or up and down.  It consists of a 40106 for a clock driving a 4029 binary counter and a 4051 multiplexer.  The multiplexer drives 4066 switches, and there are a pair of 4013 flip flops to control the up/down count.  I'll post a schematic when I get one drawn up, if anyone is interested.

https://www.youtube.com/watch?v=ayBFpYwqOxQ