Last Updated or created 2024-04-25

Using the Korg CA-20

On the side you see the bagpipe tuning.
In the past, I replaced one of the LEDs. But now it didn’t turn on any more.

So I took it apart, and what did I miss when replacing the LED?
This tuner has more functionality hidden.

This is more often the case with devices, because it keeps the costs down. Make one print and use in many.
(See the diskman story below)

When looking at the cover plate, you see only 4 buttons. But there are six!
Then I noticed some solder pads with the lettering Buzz.
So button 5 and 6 are for a metronome!
You see the little piezo buzzer I got from my component’s drawer.

A similar hack was the Diskman player in the 90s.

It was something like the model below.

There was only play/pause stop and skip whole track or back whole track.

When opening, I figured out which chips were doing what.
Saw that some signals were not connected to the control panel.
These were : Fast forward, and reverse. And skip 30 seconds.

So I glued some buttons on the side and presto.

A few years later, I took it apart and connected a DB-9 connector to it.

Now I could control the playing using my Amiga!

Some drawings I found

Will post chip info, and more when found.