# Core API Calls

Call | Purpose
TextToSpeechStartup() (Windows) TextToSpeechStartup() (UNIX) | Initializes and starts up text-to-speech system. • In Windows, the user defines the window handle to which post messages can be sent. • In Tru64 UNIX, the user defines the callback routine. The calling application can then receive index marks, memory buffers, or status information through the above operating system dependent mechanism.
TextToSpeechStartupEx() | Initializes and starts up text-to-speech system. The user defines the callback routine that can be called when index marks, memory buffers, or status information needs to be sent to the calling application.
TextToSpeechSpeak() | Speaks text from a buffer.
TextToSpeechShutdown() | Shuts down the text-to-speech system.