|=========================================================================| | | | Intel External Modem Serial Port Pin Assignments | | | |=========================================================================| GENERAL INFORMATION Intel external modems use a DB25S (D-shell, 25-pin female) connector for the RS-232 serial port. The connector on the modem's end of the cable must be a DB25P (D-shell, 25-pin male) connector. The connector on the opposite end must mate to the serial port on your computer or terminal. Consult the device's user guide for more information on its connector. ASYNCHRONOUS CABLE CONSTRUCTION This diagram shows you how to build a cable good for synchronous and asynchronous cummunications. Most PCs, however, use RS-232 asynchronous serial ports. For synchronous communications, you must use a synchronous serial port. NOTE: You must use shielded cable and shielded connector backshells when building the cable. |===========================================================| |Modem End | Signal |Signal | DB25 | DB9 | |Pin Number| Name |Direction| Pin #| Pin #| |==========|========================|=========|======|======| | 1 |Case Ground | N/A | 1 | | |----------|------------------------|---------|------|------| | 2 |Transmitted Data (TD) | <----- | 2 | 3 | |----------|------------------------|---------|------|------| | 3 |Received Data (RD) | -----> | 3 | 2 | |----------|------------------------|---------|------|------| | 4 |Request to Send (RTS) | <----- | 4 | 7 | |----------|------------------------|---------|------|------| | 5 |Clear to Send (CTS) | -----> | 5 | 8 | |----------|------------------------|---------|------|------| | 6 |Data Set Ready (DSR) | -----> | 6 | 6 | |----------|------------------------|---------|------|------| | 7 |Signal Ground | N/A | 7 | 5 | |----------|------------------------|---------|------|------| | 8 |Carrier Detect (CD) | -----> | 8 | 1 | |----------|------------------------|---------|------|------| | 15 |Transmit Data Clock | -----> | 15 | | |----------|------------------------|---------|------|------| | 17 |Receive Data Clock | -----> | 17 | | |----------|------------------------|---------|------|------| | 20 |Computer Ready (DTR) | <----- | 20 | 4 | |----------|------------------------|---------|------|------| | 22 |Ring Indicator (RI) | -----> | 22 | 9 | |----------|------------------------|---------|------|------| | 24 |External Transmit Clock| -----> | 24 | | |===========================================================| =========================================================================== March 2, 1992 Intel FaxBACK # 4300 Page 1 |=========================================================================| | | | Intel External Modem Serial Port Pin Assignments | | | |============================= (continued) ===============================| 2400EX/2400EX MNP CUSTOM CABLE DIAGRAM Cable specification for connecting 2400EX to _________________________. |============================================================| | Modem End | Signal | Signal | Other End | |Pin Number | Name | Direction | Pin Number | |===========|=======================|===========|============| | 1 | Case Ground | N/A | | |-----------|-----------------------|-----------|------------| | 2 | Transmitted Data (TD) | <----- | | |-----------|-----------------------|-----------|------------| | 3 | Received Data (RD) | -----> | | |-----------|-----------------------|-----------|------------| | 4 | Request to Send (RTS) | <----- | | |-----------|-----------------------|-----------|------------| | 5 | Clear to Send (CTS) | -----> | | |-----------|-----------------------|-----------|------------| | 6 | Data Set Ready (DSR) | -----> | | |-----------|-----------------------|-----------|------------| | 7 | Signal Ground | N/A | | |-----------|-----------------------|-----------|------------| | 8 | Carrier Detect (CD) | -----> | | |-----------|-----------------------|-----------|------------| | 20 | Computer Ready (DTR) | <----- | | |-----------|-----------------------|-----------|------------| | 22 | Ring Indicator (RI) | -----> | | |============================================================| =========================================================================== March 2, 1992 Intel FaxBACK # 4300 Page 2 |=========================================================================| | | | Intel External Modem Serial Port Pin Assignments | | | |============================= (continued) ===============================| 14.4EX/9600EX CUSTOM CABLE DIAGRAM Cable specification for connecting 14.4EX/9600EX to ______________________. NOTE: You must use shielded cable and shielded connector backshells when building cables for this modem. |==============================================================| | Modem End | Signal | Signal | Other End | |Pin Number | Name | Direction | Pin Number | |===========|=========================|===========|============| | 1 | Case Ground | N/A | | |-----------|-------------------------|-----------|------------| | 2 | Transmitted Data (TD) | <----- | | |-----------|-------------------------|-----------|------------| | 3 | Received Data (RD) | -----> | | |-----------|-------------------------|-----------|------------| | 4 | Request to Send (RTS) | <----- | | |-----------|-------------------------|-----------|------------| | 5 | Clear to Send (CTS) | -----> | | |-----------|-------------------------|-----------|------------| | 6 | Data Set Ready (DSR) | -----> | | |-----------|-------------------------|-----------|------------| | 7 | Signal Ground | N/A | | |-----------|-------------------------|-----------|------------| | 8 | Carrier Detect (CD) | -----> | | |-----------|-------------------------|-----------|------------| | 12 | Speed Indicator | -----> | | |-----------|-------------------------|-----------|------------| | 15 | Transmit Data Clock | -----> | | |-----------|-------------------------|-----------|------------| | 17 | Receive Data Clock | -----> | | |-----------|-------------------------|-----------|------------| | 20 | Computer Ready (DTR) | <----- | | |-----------|-------------------------|-----------|------------| | 22 | Ring Indicator (RI) | -----> | | |-----------|-------------------------|-----------|------------| | 24 | External Transmit Clock| -----> | | |==============================================================| =========================================================================== March 2, 1992 Intel FaxBACK # 4300 Page 3 |=========================================================================| | | | Intel External Modem Serial Port Pin Assignments | | | |============================= (continued) ===============================| MACINTOSH 8-PIN SCC MODEM CABLE Cable specification for connecting an Intel external modem to an Apple Macintosh. NOTE: You must use shielded cable and shielded connector backshells when building cables for this modem. |============================================================| | Modem End | Signal | Signal | Macintosh | |Pin Number | Name | Direction | Pin Number | |===========|=======================|===========|============| | |- 1 | Case Ground | N/A | | |--|--------|-----------------------|-----------|------------| | | 2 | Transmitted Data (TD) | <----- | 3 (TX-)| |--|--------|-----------------------|-----------|------------| | | 3 | Received Data (RD) | -----> | 5 (RX-)| |--|--------|-----------------------|-----------|------------| | | 4 | Request to Send (RTS) | <----- | 1 (HSO)| |--|--------|-----------------------|-----------|------------| | | 5 | Clear to Send (CTS) | -----> | 2 (HSI)| |--|--------|-----------------------|-----------|------------| | | 6 -| | Data Set Ready (DSR) | -----> | | |--|-----|--|-----------------------|-----------|------------| | |- 7 | | Signal Ground | N/A | 8 & 4 (GND)| |--------|--|-----------------------|-----------|------------| | 8 | | Carrier Detect (CD) | -----> | | |--------|--|-----------------------|-----------|------------| | 20 -| | Computer Ready (DTR) | <----- | | |-----------|-----------------------|-----------|------------| | 22 | Ring Indicator (RI) | -----> | | |============================================================| NOTE: On the Intel modem end (DB25 connector), short pins 1 and 7 together in addition to shorting pins 6 and 20. On the Macintosh end (SCC 8), short pins 8 and 4 together. If you look at the pins of the 8-pin SCC connector, they are numbered like this (the block at the top represents the key which prevents you from incorrectly inserting the connector): * 6 7 8 3 4 5 1 2 =========================================================================== March 2, 1992 Intel FaxBACK # 4300 Page 4