\pard\tx520\tx1060\tx1600\tx2120\tx2660\tx3200\tx3720\tx4260\tx4800\tx5320\f0\b0\i0\ul0\fs28\fc0 MIDI Macintosh Serial Cables RS232 RS422\
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Q: How can I get a MIDI interface to work with the new 68040-based NeXT computers?\
Q: What cable do I need to connect between the 68040 serial port and a Macintosh-compatible serial device?\
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A: NeXT changed the serial ports on the 68040-based systems to support hardware flow control, which is an important feature for modems. The old ports were RS-422 format, and the new ones are RS-423, which is RS-232-compatible. While this change won't affect all devices, some devices will no longer work with a standard Macintosh serial cable, including most MIDI interfaces. The symptom is that MIDI works in one direction only (in but not out, or vice versa), or not at all. \
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Macintosh-style MIDI interfaces that adhere rigorously to the RS-422
\pard\tx520\tx1060\tx1600\tx2120\tx2660\tx3200\tx3720\tx4260\tx4800\tx5320\fc0 should also work with the new RS-423 serial ports, if the right cable is used (see below). However, many MIDI interfaces don't work, even with the new cable. One MIDI interface that is known to work (with the new cable) is the Studio 3 from Opcode Systems. Opcode will also modify existing Pro Plus interfaces to work with the 68040 computers using the standard Macintosh serial cable. Contact Opcode at (415)369-8131 for details.\
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The appropriate cable is the last one given in the
\b zs
\b0 man page ("NeXT 68040 to Some RS-422 Devices"). It is available from Computer Cables and Devices in Connecticut; ask for part number CCD 1137 (which they also refer to as the "unlike" cable, in contrast to the "like" cable used to hook two 68030 machines or two 68040 machines together). See NextAnswers hardware.470 for more information about this company.\
