Texas Instruments - Magic Melody / Der singende Spielball

Texas Instruments - Magic Melody/ Der singende Spielball (a toy that sings with lovely female robot voice)

This ball- shaped toy music box from 1992 plays 6 monophonic melodies and 6 sung (!) German children songs using a Texas Instruments CPU that contains a very gritty sounding LPC (speech synthesis) synthesizer (based on wavetables?). The songs are selected by rotating the ball in a way that the picture of the selected song faces up. The German name "Der singende Spielball" means "The singing play- ball".

main features:

6 monophonic, short German children song melodies:

Ein Männlein steht im Walde
Hänschenklein
Auf einem Baum ein Kuckuk
Backe, backe Kuchen
Der Mond ist aufgegangen
? (a picture with pears)

6 sung German children songs: (unfortunately very short, only 1 stanza per song)

Alle Vögel sind schon da
Kommt ein Vogel geflogen
Alle meine Entchen
Häschen in der Grube
Es tanzt ein Bi-Ba-Butzemann
Fuchs Du hast die Gans gestohlen

song selection by tilt sensors consisting of steel balls rolling in hollow metal cylinders
gritty sounding monophonic LPC (speech synthesis) sound generator with a charming female voice. The non- sung melodies timbre sounds like a sine wave signal with much aliasing noise. The CPU (Texas Instruments 305674T, ©1992, CSM 11159AN) has a 16 pin DIP case (no black blob/ COB).
unpleasantly resonant (can- like) droning and dull sounding speaker
no volume control
on/off switch
crystal clocked

eastereggs:

Shitshooting (by battery wiggling) makes the sound CPU play strange noises (e.g. similar like poor shortwave radio reception).

notes:

When I bought this toy on flea market, the tilt sensors responded very badly and only reacted on severe hits or shaking. To open the case I needed to saw a welded seem between the 2 plastic hemispheres apart, and additionally there were screws hidden under 4 plastic foil picture stickers (those got slightly damaged by the removal). Inside is a blue, 5 edge prismatic (roughly cylindrical) plastic subchassis that is held by shock absorbing polyethylene foam. The subchassis has the speaker at one end and the battery case at the other; in between is the PCB, which contains besides the CPU relatively many discrete parts (resistors, transistors etc.). There are 5 slanted ball tilt sensors those each consist of a metal cylinder containing a small and 2 tiny steel balls those roll against an metal end contact in a certain position. The sensors were coated with a smeary mess of hardened machine oil, which had insulated them and thus prevented proper signals. After thoroughly cleaning these parts with soap water and isopropanol the contacts functioned again, but it was a very unpleasant and fumbly job to re- assemble the unit, because the balls continuously tend to fall out of the cylinders, their cables break easily and various small notches prevent components from being inserted wrongways. This way it needed much trial and error to re-assemble everything. Now the sensors respond sufficiently again.

I have absolutely no clue why Texas Instruments as well screwed as welded the case tight; possibly they thought that children toss this ball- like toy around so badly that case would crack apart when only held by screws. IMO this is one of the most awkward to repair electronic toys. I guess that at the bottom a detachable battery cover with a 12th picture is missing, because there are still the notches to hold it.

The hardware has much similarities with my yellow animal train sound toy, which also uses a similar Texas Instruments CPU to synthesize gritty animal voices. Unlike the latter, I didn't add modifications to the Magic Melody ball, because its hardware is very awkward to dismantle and (unlike the animal train) likely badly suited as an instrument. But I love the gritty, charming, grandma- like electronic voice of this toy - it reminds to strange science fiction fantasies about a robot nurse or the like.

*removal of these screws voids warranty...*

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