| 摘要 |
The circuit for communicating with different type MODEMS consists of a MODEM circuit (10), and an automatic data way switching circuit (20). The MODEM circuit includes a microprocessor (U1), an I/O port (U0) connected to a computer, a pulse and touch tone circuit (U2), a low-speed MODEM (U3), a high-speed MODEM (U4), and an I/O control circuit (U7). The switching circuit includes multiplexer (U5, U6) controlled by the microprocessor (U1).
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