Yamaha TYU-40

Yamaha TYU-40 (polyphonic squarewave toy keyboard with key lighting and pitchbend)

This small squarewave toy keyboard has only 1 main voice sound (piano) and 4 rhythms, but it has a key lighting function to learn keyboard playing. Like the Yamaha PC-100 not the keys itself but a row of small LEDs above them light up, but instead of fragile PlayCards, there are only 16 melodies built-in the internal ROM. The musics were selected by so- called "Music Card" dummy cartridges those only hold down 2 buttons in the cartridge slot by 2 protruding pins. Very unusual is that this thing has a pitchbend wheel (which simply controls the internal CPU clock speed). This keyboard was certainly the successor of my Yamaha TYU-30.

Unlike the TYU-30, the TYU-40 is black and exactly rectangular (nothing has round corners); also the sliders are vertical and it generally resembles closer the style of PortaSound non- toy keyboards. The placement and design of the acryl covered card slot is a naughty imitation of the ROM- Pack slot of a Casio PT-82.
(This is an eBay photo; my specimen misses all the shown accessories.)

main features:

25 mini keys with small red key lighting LEDs at their upper end.
only 1 fixed main voice sound (piano)
4 rhythms {waltz, swing, rock, latin}
"music" mode switch {auto play, free tempo, melody cancel, rhythm play}
tempo buttons
transpose buttons (-5..+6 semitones)
volume slider (4 steps)
pitchbend wheel (simply controls system clock speed =>rhythms speed & pitch changes too!)
digital squarewave sound generator with 4-note polyphony (for main or chord voices) + 1 bass voice + electronic sounding percussion. (The sound hardware is likely identical with the YM2163 chip of my Testron keyboard, but was integrated into the single- chip CPU of the instrument.)
fake cartridge slot for "Music Cards" which hold down 1 or 2 of 2 buttons
9V..12V AC adapter jack, line out and microphone jack

notes:

It takes quite long to understand why the thing often refuses to play and other times works well, until I read in the TYU-30 manual that to get the musics to play, you must first hold down "start/ stop" button, then press the key with the melody number and while still holding that key release the "start/ stop" key. This reminds me much of my Atari 8 bit homecomputer reset button sequence for cassette loading, but for operating a children toy this is really a little hard and rather resembles the procedure for unlocking the child lock function of a badly designed VCR.

I bought this keyboard with the Music Cards missing, but since they were dummies, I simply made my own ones from 2 pieces of sheet plastic, some screws (for the pins) and hotglue. Also the battery spring of my specimen was rusted off by leaked battery remains, and the analogue pitchbend potentiometer suffers from dirt and the inaccuracy of its mechanical centring spring, thus the pitch tends to vary after releasing the pitchbend wheel. There exist exactly 3 cards with the following melodies:

music card 1

Beat It
Just The WaY You Are
We've Only Just Begun
Days Of Wine & Roses
Flashdance
Endless Love

music card 2

Michael, Row The Boat Ashore
Oh, Susanna
La Paloma
When The Saints Go Marchin' In
Frère Jacques (Brother John)
Londonderry Air

music card 3

I've Been Working On The Railroad
Twinkle, Twinkle, Little Star
Auld Lang Syne
Joy To The World
Jingle Bells
Silent Night

(I downloaded the manual to identify them.) Due to they are all built into the internal CPU, there is no way to expand this library.

*removal of these screws voids warranty...*

	back