Re-purposing an old MIDI interface

Re-purposing an old MIDI interface - part 1

I hate to throw things away. I've had an old serial port MIDI interface lying around the house for 20 years doing nothing. It was from Windows 3.1 days, and was non-upgradable to Windows 95. But now it's time to bring it back to life.

First some pictures...

The Original Box

Unboxed

MIDI ports at the other end

25-pin serial port at one end

My idea is to make it into a very simple sequencer based on the Arduino, with both MIDI in and out capability plus a bunch of other features whilst retaining the original box for nostalgia. So let's take a look inside and see if there is anything that can be salvaged...

Internals

Well, not much really, there are the ports which I can definitely use plus a few resistor, diodes and capacitors, some of which may be usable in my new project but probably not worth the hassle of unsoldering. Then there are 2 transistors, which I will save for other projects and what looks like an optocoupler on the MIDI-in side. The rest are what I assume are custom eproms, since they are unmarked, so no use to me.

Let's take a close look at the optocoupler...

GE CNY17I 8711 optocoupler?

I quick google around, and I find a data sheet, and a bit more googling around and I find someone has used one to build an Arduino MIDI-in interface so I will try to salvage that.

Edit: I'm not 100% sure about that datasheet for the optocoupler, but I can't find anything with the "I" suffix. Here is another datasheet which seems to be a generic CNY17

Edit: I think my CNY17I was made by General Electric but is now an obsolete part. I will make a small MIDI in circuit to test it though. I'm pretty sure the pinout will be the same.

Thats it for now, I'll be back later with some design information, schematics, and board layouts.

Comments

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