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Miracle Piano Guide - NES PC Serial Cable - Foot Switch Mod

Posted: Mon Mar 26, 2012 4:08 pm
Miracle Piano Guide - NES Cable - Foot Switch Mod

UPDATE - Added PC Cable Instructions in the 2nd Reply


The Miracle Piano came out in 1990 and can be hooked up to the NES, SNES, Genesis and computers to assist in learning how to play the piano. A custom serial cable for each console or computer communicates between the Piano and Console or PC to detect piano key presses and play back songs. This is an obscure Piano Keyboard that sometimes might be found online at a high price or a Rare chance discovery at a Thrift Store or Swap Meet. Surprisingly, the NES cart is more common then the piano keyboard, it can be found inexpensively online.

The Miracle Piano is no longer manufactured and can only be bought used. Sometimes the piano is missing the power supply, most of the time the Sustain Foot Pedal and proprietary serial communication cable is missing. In this Guide I will show how to replace the missing parts and build a custom Communication Serial Cable. I will focus on the NES, other systems can be built following the same procedure. At the end of the OP are references for other systems.

First a little background information on the Miracle Piano.

weltenschule wrote: ... Piano.html

The initial retail price in 1990 was about $500. Beside for PC (DOS or Windows 3.11) also software versions for Amiga and even for the Nintendo NES and Sega Megadrive Genesis game consoles were released. (Despite the game consoles this is not just a toy keyboard but has a far higher sound quality than e.g. My Music Center.) The hardware of this instrument was manufactured by Antex and the software by The Software Toolworks.

Miracle Piano Main Features

- 49 velocity sensitive fullsize keys (non- weighted)
- 2 built-in speakers (stereo, but rather thin and hollow sounding)
- polyphony 16 notes (only 8 notes with stereo preset sounds)
- 128 preset sounds (including 3 drum kits and 2 effect kits)
- all functions selected through only 8 buttons
- volume +/- buttons (10 steps) those also select other functions
- 6 function buttons {1= "piano / melody 1", 2= "vibraphone/ bass", 3= "harpsichord/ melody 2", 4= "elect piano/ percussion", 5= "organ/ accompany", 6= "synthesizer /select"} with each a green indicator LED
- 9 default key split modes {classical, rock, jazz, blues, rap, latin, country, cathedral, new age} those assign each a set of 6 OBS preset sounds to the 6 buttons
- "library select" mode to select preset sounds by number (function button 6= sound "0", 1= "step up", 2= "step down", 3= "10 steps up", 4= "10 steps down")
- 10 step green LED indicator bar (for mode and volume)
- wavetable sound generator: all sounds based on medium and high resolution samples with partly audible zipper noise.
- no battery compartment
- jacks for AC- adapter, headphones, line out, foot pedal, MIDI in/ out and special serial port

Here are pics of a new Miracle Piano in a box, you can see the Foam Foot Pedal and NES cable:
Extra Connections
Here is what makes the Miracle Piano unique. The back has connections for Stereo RCA Audio out, Headphone Jack, Foot Pedal, Power Input, Midi In and Out and a proprietary 25 pin Serial connection. The Midi connections are standard and can be used with a PC or Mac to control the Piano. Play sounds, beats and songs controlled by the computer!


Power Supply
Any Power Supply that has AC 12 volt 1 Amp/1000 Milliamps output will do. The voltage must be 12 volt and the amperage can be higher but not lower. The AC voltage is uncommon, DC is the normal output on most power supplies.

Piano Education wrote:

The OEM power supply for the Miracle is a 12 volt AC transformer, rated to deliver 1 amp. Since the current used is AC, there is no "polarity" to concern one's self with. Any power supply that can supply AC at this voltage and amperage and has a compatible connector for the keyboard will work. One of our visitors says that she has successfully tested the Radio Shack 9-13VAC/800mA AC-to-AC Adapter for AT&T Answering Machines, Catalog #: 273-1631, $15.99 list, with her Miracle system. Although this adaptor is rated for 0.8 amps, rather than 1 amp, it has been discontinued by Radio Shack. Just about any adjustable voltage AC-to-AC adapter rated for around 1 amp will work, so long as you set the adjustable voltage to 12 V, on any AC transformer you might use with the Miracle.

Foot Pedal
The Foot Pedal connection allows a sustain feature in the Miracle Piano. The two prongs are very close to the power switch. Even if a sustain pedal is not added, a good idea to obtain a connector to prevent accidental shorting. The connector can be found at any electronics retailer such as Radio Shack or Frys. The square hole in the back of the piano is small. I had to file down the sides of a connector as well as opening up the hole a little in the back of the piano.

As for the Foot Pedal, any digital switch can be used that shorts the two prongs. Be sure it is not analog such as a game driving controller gas pedal. Switches can be found at music stores or a sewing machine foot switch or one can be built.

I already have a higher quality foot pedal at home, better then the original foam version. Anyone remember the Court Tape Recorder Foot Switch I bought a almost a year ago? I was going to make a Track and Field style controller out of it by gutting a PC keyboard encoder. Never did since it would have been for only a few games.

The pedal is perfect for the piano, but I had a concern. I'm almost positive the original Foot switch would just short the two prongs, but what if there is a resistor? Downloading the manual and schematics did not help, it took a brave YouTube poster to convince me. PAPERCLIPS?! :shock:

Any switch that completes the connections of the two pins works just fine.
Okay the Court Data Recorder Foot Switch works, an easy cut the end and solder in the right plug from my local electrician store. I spliced in both limit switches so either foot pedal produces the sustain feature.

Custom Serial Cable
The Miracle Piano has a 25 pin Serial Port, strangely it is upside down compared to a normal position of connector with more pins on top. The upside down connection is an important point to identify which pins will be used for the custom cable. I knew the NES can be hooked up, a search of the specialized cable shows a little on the pricey side. I have plenty of spare NES controllers to rob the cable with the game console Plug. The rest of the parts can be found at the local Electrical Supply retailer.

1. NES Controller - For the cable assembly
2. 25 Pin Serial Male Connector - Exposed Pins
3. 25 Pin Serial Connector Housing - Plastic or Metal
4. Electrical Tape - Black matches the cable
5. Heat Shrink - Various sizes
6. Lighter - Barbecue Lighter works well
7. Solder and Soldering Iron
8. Zip Tie - If no lock screw in housing
9. MultiMeter - If 3rd party controller, 1st party described below

The serial connector can be the type that has preinstalled pins or the pins can be bought separately. Preinstalled pins are harder to solder, but since there are only four wires I went this route. The plastic screw in the bag anchors the cable so a Zip Tie is not needed.

Miracle Piano NES Cable Parts.jpg
Miracle Piano NES Cable Parts.jpg (222.13 KiB) Viewed 29711 times

The NES controller plug and cable will be used with the 25 pin serial connector. Either desolder the wires or just cut the cable at the NES controller end. Do not toss the vintage NES controller, it might come in handy for parts or a future mod.

CRTGAMER wrote:I kept the NES controller, it can be used later for a custom controller. The NES controller buttons can easily be jumped to an Arcade Digital stick and buttons to compliment the stick with NES controller style game play. I am already envisioning a nine pin connector add on to my Wii Tatsunko Capcom Arcade Controller, but that will be a Guide later on. :D

The NES controller mod is done, a direct plug in to a Wii Remote.

Strip away about two inches of the insulation from the NES controller cable to expose the inner five wires, then strip a little off each wire. If a 3rd party controller is cannibalized, the wire colors might be different. To be sure of the connections, a good idea to test each wire with a MultiMeter to verify the pin locations.

Looking towards the NES console as if connected, the pins are laid out with four on the left and three on the right. The NES connector pins for a 1st party Nintendo controller read starting from the TOP LEFT, note the top right has a larger number.

Left Side From Top
Pin 1 - Brown
Pin 2 - Red
Pin 3 - Orange
Pin 4 - Yellow

Right Side From Top
Pin 7 - White
Pin 6 - No Wire
Pin 5 - No Wire

The serial connector housing is designed for a twenty five wire lead, so the NES five wire cable has to be made thicker. Make sure this is done before soldering any wires. Electrical tape can be used, but heat shrink offers a cleaner look.

CRTGAMER wrote:Place Heat Shrink in the cable before any soldering is done. If there is no lock screw in the connector housing, a zip tie wrapped around the wire, will prevent the wires from being pulled from the soldered assembly.

Place an initial small wrap of Electrical Tape to make the cable thicker. Follow thru by covering with Heat Shrink. Use the Lighter to reduce the size of the Heat Shrink. Add a layer and heat each layer one at a time, use a larger sized Heat Shrink if needed. When completed the insulation should be the same thickness as the connector housing cable hole.

Solder the wires
Check and double check the pin locations. There are thirteen pins on top and twelve on the bottom. Online searches have instructions, but are not clear due to the serial pin connected upside down. Refer to the pic below for the exact locations, follow the pin numbers embossed on the connector plastic insulator.

The White wire of the NES controller is not used, it can be cut back.

Serial Pin 19 - NES Pin 2 Red
Serial Pin 13 - NES Pin 3 Orange
Serial Pin 10 - NES Pin 4 Yellow
Serial Pin 7 - NES Pin 1 Brown


CRTGAMER wrote:It is important to scrutinize from which side the solder points are located. At first I had mine reversed, I looked at the piano end when following instructions I found online. The instructions are vague as to the view direction. All the pin connections online described were looking towards the NES console, even the Miracle Piano connector. The pic below has the the correct wire soldered locations, see the charts above to match the NES controller plug end.

Miracle Piano NES Cable Solder Connections.jpg
Miracle Piano NES Cable Solder Connections.jpg (240.04 KiB) Viewed 29711 times

Be careful, the thin cable wires can easliy break off from the solder connections. Glue can be used to reinforce the area but not needed if the cable is anchored. Install the wire assemby in the 25 pin housing, then tighten the two halves of the housing shell together. Push the cable in slightly to give a little slack then tighten the cable anchor. If a Zip Tie is used it should be placed inside the housing as to prevent any soldered wire separation if the cable is pulled. The piano does not have threads for the anchors at its 25 pin port so leave the connector cable connection lock screws off.

Testing the Miracle Piano
Plug the custom cable into the piano and to the Left Number 1 Port of the NES console. Plug a NES controller into the right number 2 port. Plug in the power plug for the piano then turn it on. Pop in the NES Miracle Piano cart, power on the NES. A Software Toolworks screen will pop up followed by the Miracle Piano screen if the serial connection is detected to the piano. The Piano will start playing an intro song controlled by the NES. Use the NES controller plugged in the number 2 port to select lessons, songs or a game.

Right Click for a larger pic.

Miracle Piano NES Cable - NES Controller - NES Cart.jpg
Miracle Piano NES Cable - NES Controller - NES Cart.jpg (215.75 KiB) Viewed 29711 times

The Miracle Piano senses how hard the keys are struck, press softly for quiet passages, bang on the keys for a loud repertoire. The Sustain Foot pedal is a nice bonus feature which adds depth to a song. Even though the game software is from 1990, it actually has good sounds since the piano is providing the music. Discover hidden animal sounds built in the Miracle Piano and test every Piano key tone by tapping the direction keys. During the lessons, the NES cart can detect which piano key is pressed and give a visual cue on the TV. It also has games that can be interacted from the Miracle Piano. The songs included in the lessons start out as simple single key input all the way to two handed chorded functions. I will never become as good as Beethoven, but never know what hidden talent I might possess. I am utter crap when it comes to Karoke, maybe fare better using the fingers instead of my voice. I can always let the NES cart play the songs. 8)

Game Faq: ... faqs/59003
Piano Education FAQ:
NES Manual:
Make a Cable:
Atari Age Guide: ... cle-piano/
Quick Start and Key Template:

Right Click for a larger pic.


Re: Miracle Piano Guide - NES Serial Cable and Foot Switch M

Posted: Mon Mar 26, 2012 4:09 pm
Miracle Piano PC Data Cable
There are numerous instructions online for making a Miracle Piano Data Cable, but with contradicting solder connections in the wires. Thanks to Luigiman who sold me an Original Miracle Piano PC Cable, Software and Manuals, I have confirmed exactly the correct pin layout for building your own Miracle Piano PC Data Cable. :idea:

1. 25 Pin Serial Male Connector - Exposed Pins
2. 25 Pin Serial Connector Housing - Plastic or Metal
3. 9 Pin Serial Female Connector - Hidden Pins
4. 9 Pin Serial Connector Housing - Plastic or Metal
5. 4 Wire with Shielding Wire Cable Assembly
6. Electrical Tape - Black matches the cable
7. Heat Shrink - Various sizes
8. Lighter - Barbecue Lighter works well
9. Solder and Soldering Iron
10. Zip Tie - If no lock screw in housing

DB9F to DB25M Modem Serial Cable

Be careful, this can fry your PC and or the Miracle Piano since it is not rewired correctly. It does not have all the correct pins connected in the DB25 plug.


Follow the OP above for the soldering and assembly of the PC cable. Note that the PC Cable uses different pins compared to the NES cable. This confirms why the Serial Cable on the Miracle Piano needs 25 pins even though only a few are used. Depending on what system is used, a different pin layout is required.


Solder Connections - Looking At The Back Of Connectors
DB9 Pin 1 - DB25 Pin 7
DB9 Pin 3 - DB25 Pin 12
DB9 Pin 4 - DB25 Pin 11
DB9 Pin 8 - DB25 Pin 13, 24, 25, Ground (Outer Connecter Metal)
DB9 Shield - DB25 Shield

The official Miracle Piano is completely shielded and connected to both the DB9 and DB25 outer metal connectors. Perhaps this is needed due to the PC putting out more electrical interference. I posted a closeup JPG of a Female DB9 connector a few Replies below which shows the pin numbers.

Right Click Attached Pics for a larger view
Picture below pulled from the Piano Education site linked in the OP. The connections are shown looking at each outer end of the plugs, NOT FROM THE SOLDER SIDE.
Miracle Piano PC Data Both Facing Ends Of Cable.gif
Miracle Piano PC Data Both Facing Ends Of Cable.gif (1.71 KiB) Viewed 27643 times

NES and PC Data Cables - The official PC cable is missing DB25 pins 1, 4 and 20.
Miracle Piano NES and PC Cable.jpg
Miracle Piano NES and PC Cable.jpg (196.7 KiB) Viewed 27643 times

Miracle Piano Manual - Software - PC Data Cable - MIDI Cables :mrgreen:
Miracle Piano Manual - PC Cable - Software.jpg
Miracle Piano Manual - PC Cable - Software.jpg (231.08 KiB) Viewed 27643 times

Re: Miracle Piano Guide - NES Serial Cable and Foot Switch M

Posted: Mon Mar 26, 2012 7:36 pm
by DinnerX
Well now that I know it's so easy to make cables for, if I ever see an incomplete miracle piano I'm definitely buying it. Nice guide CRTGAMER. 25-Pin connector diagrams sure are easy to get backwards aren't they? :lol:

Re: Miracle Piano Guide - NES Serial Cable and Foot Switch M

Posted: Sun Mar 24, 2013 8:11 pm
Michi wrote:Making the cord myself looks to be surprisingly easy (and fairly cheap in case I screw up horrifically), so I think this will be an excellent chance for me to get some much needed soldering experience. When I go to RadioShack to get the parts next week I'm going to pick up a spare board and some capacitors so I can get some practice in for when I eventually try that Genesis S-Video mod :D

Quick question, though. When I called, they said they were out and wouldn't have this in until this week, but this is the right 25 pin connector, correct:

Just want to make sure, as this is something I haven't done before.

For the soldering Iron get a Pencil Iron around 25-30 watts. This will be light with a small tip for an easier control over the larger trigger controlled solder guns. Be sure the solder is Rosin (Flux) core in small diameter solder wire.

Start by tinning the point of the iron all the way around the tip. Once the solder sticks, heat the component and apply the solder to the component and not the Pencil iron. This ensures good solder flow onto the parts being soldered. When dealing with electronic parts, work fast to avoid heat damage.

That 25 pin you linked is the right connector, it has the male pins. Be sure to get the matched housing for it, no need to install the cable connection lock screws since the piano has no threads for them. Maybe also order the NES Miracle cart so you can verify the mod right away.

Be sure of the pin locations when soldering the wire, I had mine backwards when refering to other guides online. The attached picture in the OP clearly shows the correct pin locations, using a 1st party NES controller will have the matched colors on the wires.

Miracle Piano Guide - NES PC Serial Cable - Foot Switch Mod

Posted: Thu Apr 04, 2013 4:24 pm
I verified an official Miracle Piano PC Data Cable, posted instructions how to make one in the 2nd Reply above. :D

DB25 Male pin layout solder connection side
DB25 Pin Solder Connection Side Male.jpg
DB25 Pin Solder Connection Side Male.jpg (59.88 KiB) Viewed 27643 times

DB9 Female pin layout solder connection side
DB9 Pin Solder Connection Side Female.gif
DB9 Pin Solder Connection Side Female.gif (2.56 KiB) Viewed 27643 times

Close up of Female DB9 connector
DB9 Female.jpg
DB9 Female.jpg (396.82 KiB) Viewed 27643 times

Re: Miracle Piano Guide - NES PC Serial Cable - Foot Switch

Posted: Fri Jun 21, 2019 3:05 pm
by TinyM
The 'Miracle Piano Sustain Feature' YouTube video appears to no longer be available. Could you post a description of what connector and steps you used to get the court tape recorder foot switch to work with the Miracle?

Thanks so much!

Re: Miracle Piano Guide - NES PC Serial Cable - Foot Switch

Posted: Tue Jul 30, 2019 9:50 pm
TinyM wrote:The 'Miracle Piano Sustain Feature' YouTube video appears to no longer be available. Could you post a description of what connector and steps you used to get the court tape recorder foot switch to work with the Miracle?

Thanks so much!

Any foot switch; that provides a connection of the two pins from the Miracle piano.