The ML2240 is a 4-channel mixing speech synthesis device which connects an external ROM expanded up to 128-Mbit (maximum). This ML2240 allows to select the playback method from the 8-bit PCM, non-linear 8-bit PCM, 16-bit PCM, 2-bit ADPCM2, and 4-bit ADPCM2 algorithms. And the sound volume is adjustable as well. The ML2240 incorporates a 14-bit D/A converter, and low-pass filter. It is easy to configure a speech synthesizer by externally connecting a power amplifier and a CPU to the ML2240.