Talking Alarm Clock


Talking alarm clock knew one sentence: "Three, two, one, go!". Which I've borrowed from Grand Prix Simulator, old 8-bit Atari game.

Speech sythesis module was constructed from simple TTL integrated circuits and worked like this: Clock signal from oscillator was fed into chain of four 4-bit counters. These counters generated an address, which addressed the EPROM containing the sampled speech. In each byte, eight 1-bit samples were packed. They were sequentially extracted from the byte using 1-of-8 multiplexer and then fed to the speaker.

Flash player is missing to play the clip. You can download it from here.

Or you can open the clip in your media player.
Sampled speech

Talking alarm clock


Circuit diagram