Mindscape
The MIRACLE Piano Teaching System
MIDI keyboard with wavetable sound & complex piano teaching software

This is a velocity sensitive MIDI keyboard with sample based sounds, that originally came with a sustain pedal (of foam rubber?) and a complex and versatile piano teaching software.

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 sold for game consoles, this is not just a cheap 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.

There is already plenty of info about this thing available on the internet and my specimen is missing the software package and pedal, thus I only write here a few words about the keyboard itself because it is not so well documented yet. Basically it is a normal velocity sensitive fullsize keyboard with MIDI in/ out and a sound bank with 128 built-in preset sounds (including various drum kits and effect sound sets), thus it also works well without the software package. The only main difference to an average modern MIDI keyboards is that it has no built-in rhythms, no pitch/ modulation wheels and that its 128 sound bank is not based on the General MIDI standard. The latter makes it particularly interesting because its sound bank this way contains a lot of all new and partly bizarre non-GM preset sounds.

main features:

Serial No. 3021198 Beside MIDI jacks there is a special serial "Miracle port" connector, that was apparently used for PC serial port and game console versions.

notes:

Interesting is that this instrument was still made in USA and not in China like most modern keyboards. But despite its quite noble designed and slightly oversized case on the first look appears like a robust and professional stage instrument, many parts are much wackier than they appear. E.g. the control panel writing is on a loose plastic foil overlay that is only held by short flaps at its ends (there seem to exist different versions of this overlay), and the 2 protruding pointed pins of the tiny sustain pedal jack may bend or crack off easily and may react sensitive on static electricity, which is especially delicate because they are placed very close to the tiny metal power switch lever. Also the speakers are much smaller than the size of their plastic grills suggest; they are mounted in short, forward pointing funnels and have a way too hard diaphragm tension, which prevents reasonable bass response and makes the thing sound a little dull and hollow. The volume can not be set really low, which is most noticeable in sounds without velocity sensitivity. The power amplifier makes noticeable static noise at constant volume.
The speakers are much smaller than their grills. (This photo was digitally processed to show it clearer.)
The operation of the Miracle Piano is at least without the software a little awkward because the thing has no display and you need to count button presses to select a preset sound. The modes (default key splits and "library select") are selected by holding down the 6th button ("select") and stepping through the modes with the volume +/- buttons. A flashing LED in the row indicates the actual mode while a bar of lit LEDs indicates the volume setting. In the default key split modes the keyboard is split always in the middle and the sounds are selected by pressing 2 OBS buttons together (the press order determines which sound goes left and which right).

The sounds are based on samples of medium to quite high resolution. If you expect them to sound static and rather cold than you are completely right, because this thing fulfils all the well known prejudices against sample based sound bank instruments. The Miracle Piano can not do well warm and analogue timbres despite one preset sound (a lead synth with chorus) even has the naughty name "Moog". But at least some bright brass synth timbres resemble classic analogue sounds. The keyboard velocity only changes the volume of the preset sounds but never modifies the timbre in any way (despite various sounds seem to consist of 2 layered samples) and also the note duration does not change the timbre, which makes the sound quite static. The keyboard velocity behaves exponential, which makes it difficult to play medium loud notes on sustaining sounds because soft and medium strong key presses play rather quiet while slightly harder presses already rise the volume over- proportionally loud. (An acoustic piano behaves more linear.) Another annoying flaw is that the envelope of decaying sounds (like pianos or guitar) stops too soon instead of slowly fading silent. The envelopes also have a little zipper noise. Some sounds (e.g. ensemble sounds like "horns", "trumpets", "thrombones") contain a stereo chorus effect that halves the polyphony; others include a mono chorus. The chorus usually sounds a little gritty because it apparently switches the timbre (using a filter??, or phasing??) stepwise with about 4Hz (similarly like ensembles sounds on e.g. Fujitone 6A or Yamaha PSS-390). The acoustic pianos sound quite realistic; they seems to be a multi sample with 4 split points while most other sounds have none. Especially brass and bowed string timbres are realistic, but with such sustaining sounds the velocity sensitive keyboard is rather confusing because the final volume of louder growing timbres is badly controllable since the keyboard is not pressure sensitive and thus the volume of a long note can not be changed without re- playing the note because the keyboard only senses the pressure at the beginning of a note. Only a few organ and harpsichord presets have velocity disabled. The 3 human voices (called "Vox" 1..3) have a quite low resolution and the gritty chorus effect. Otherwise there is an "organ" timbre which sounds much like a higher resolution "ah" voice. The sitar is mislabelled(?) "Syntar". The "Log Drums" resembles rather a harp (at least with high notes) and the "Steel Drums" sounds nicely unrealistic (gong- like?) with a bassy bass range. Various instrument sounds exist in versions with and without sustain.

But the most interesting part of the sound bank are not the natural instrument samples (those you find nowadays on any General MIDI sound source) but the lots of bizarre effect sounds. E.g. there are 3 drum kits (high resolution samples; each sample is repeated on a few adjacent keys with different pitch) and 2 effect kits those include a lot of weird tekkno and hiphop noises like record scratches, thunder, car skidding and burp- like stuff. Also great are the 15 "Synth Pad" sounds although many of them have a percussive decay envelope (like a piano) and thus genuinely are rather lead voice than pad sounds. They include typical bright digital synth timbres and many of them have a bizarre buzzy purring bass range that resembles the sound of a ruler rattling against a desktop rim. Likely their waveforms are simply intentionally "wrongly" looped versions of the instrument samples; some sound woody while others rather resemble a looped lion roar sample or the like. But some of these sounds contain a long release phase that takes much polyphony and causes annoying random popping glitches during polyphonic play; apparently such sounds tend to overload the instrument's CPU or make it run out of polyphony, possibly also because the purring and chorus may be generated by a realtime algorithm that draws additional CPU load. Some "Synth Pad" sounds ring with a switched stereo panning effect. Another bizarre timbre is "Frogs/ Ducks", which is a thin and very dry chirping duck squawk that was possibly inspired by the "frog" sound of early Casio Consonant Vowel synthesis instruments (also see Casio MT-60 and CT-410V) although this one is definitely a sample (it gets shorter at higher octaves). Also many of the synth sounds (e.g. synth brass stuff) sound and behave very much like historical Consonant Vowel timbres and thus are likely made like these from 2 static waveforms with independent volume envelopes. Generally various timbres somewhat remind to the wavetable based Casio SA series keyboards although the latter do far more complex algorithmic tricks in their preset sound while the Miracle Piano employs only some switched ringing, chorus and panning effects.
 

hardware details

The PCB contains fairly complex digital multi-chip hardware with many special ICs or at least ICs those pretend to be special.

So the sound IC label looks a bit like sanded off and replaced with something fake to obfuscate what is going on. Also the sample ROM U16 contents seems to have scrambled address lines or be otherwise encrypted or compressed. I desoldered it, but the dumped file sounds distorted and only very grainy percussion can be heard out. It may be that the main voice timbres are only static digital waveforms those disappear in all the mess. As far I remember, the pins 22 and 24 had to be set low (GND) for readout. Strange is that even with U16 removed, the instrument still plays tone scales with velocity, although the timbres turn into random digital buzz that changes while touching the U16 IC socket. (With the main PROM removed, all LEDs are lit and nothing else works.) U20 seems to be some kind of address decoder or sample decompression/ decryption IC. Strange is also that my PCB strongly differs from the (intentionally obfuscated?) schematics found on Harmony Central (MIRB1_0.pdf, MIRB1_1.pdf). IC numbers and their PCB tags are very different; only their pin count and wiring permit identification. The schematics also mentions a "miracle keyboard main board" and "miracle sound engine", while my version has only a single PCB which is marked "©1991, The Software Toolworks, PN 800961 REV A".
 
schematics version: my version:
U15 "8032" U19 CPU= "S SCN8032HCCN40, 2206904 9101KC, (M) © INTEL 1980, (M) SIGNETICS" (40 pin DIL, Intel MCS-52)
U14 "AS0012, keyboard interface chip" U18 IC= "PART NO. 800502, ©1990 SOFTWARE TOOLWORKS, (M) AMI 9135MCL, C18113" (40 pin DIL)
U17 "27C256P" U21 main PROM= "S 27C256-20 N, 2314C02 9135 KL" with Sticker "STW 7-91, 800522, OS-2.03, C/S 3DD2" (28 pin DIL, 32KB)
U18 "6264" U22 RAM= "HYUNDAI, HY6264P-15LL, 9044D" (28 pin DIL, 8KB)
U11 "J004" U6 sound IC (DAC?)= "ST, 8500536, 29049" (40 pin DIL)
U12 "S631001-200" U16 sample ROM= "PART NO. 800504 WR 1.01, SOFTWARE TOOLWORKS INC, ©1990, (M) AMI, 9110MCH" (32 pin DIL, pinout 27C010, 128KB)
U16 "AS0013" U20 IC= "PART NO. 800601, ©1990 SOFTWARE TOOLWORKS, (M) AMI 9114MBO, C18145" (40 pin DIL)

More info about this instrument can be found on the internet. Even the original manual can be downloaded somewhere.

Wanted: I am  searching for the historical piano teaching software (PC Windows or Amiga version) that belongs to the instrument, because without it the thing is only 1/3 the fun. I already downloaded the ROM dumps of the NES and Megadrive/ Genesis cartridge versions, but since game console emulators support no MIDI connection, they don't work with the keyboard anyway. (I got a copy of the DOS software but haven't tried it yet.)
 

 removal of these screws voids warranty...    
WarrantyVoid
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