The Echo keychain chip (I remember those things as "Mini Attacker") was likely another Howltek eh Holtek product.

HT2884 8-Sound Generator + 5 Flashing LEDs:
https://www.datasheetarchive.com/pd...ype=O&term=holtek%2520sound%2520chip

But it also may be one of these:
https://honsitak-taiwan.com/products06.htm

The classic sound engine (monophonic squarewave with grainy pitch glissando envelope+shift register noise) did sounds like falling bomb, various sirens, laser, machine gun, digital phone ring, police car, ambulance etc. It was very popular in late 1980th, so the same kind of chip existed for effect sounds in monophonic Bontempi toy keyboards (e.g. "Disney Band" red/white with Mickey Mouse picture), toy DJ consoles (with internal cassette recorder), toy laser guns etc. Also the sound core of monophonic "Brick Game" LCD games may be related.

http://weltenschule.de/TableHooters/Bontempi_DisneyBand.html

I remember that my keychain toy made sound variations (faster siren speed etc.) when pressing multiple sound buttons at once. The block diagram in HT2884 datasheet suggests that it is gate logic with a little rom (envelope speed control and possible melody sequencer) instead of a complete MCU. AFAIK the keychain toys existed with at least 8 (up to 16?) sound buttons. (Mine had only 5?)

Last edited by =CO=Windler; 03/15/22 06:14 AM.
MAY THE SOFTWARE BE WITH YOU!

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