>>This page seems to offer schematics for a build-it-yourself midi port,
>>or for a simple cable incorporating two resistors that only works on a
>>special serial interface card. Or am I misunderstanding?
>You appear to misunderstand that a Mac is not like a PC and a Mac Printer
>port is not like a PC Printer port.
>Everything to connect a MIDI synthesizer to a Mac serial port is on this
>page, as the original poster requested. Whether it needs an interface or a
>printer cable for the modules that have a direct connection.
Quotes from the web site:
"Apple's bombshell in 1999 was to throw away asynchronous serial
communications altogether and to tell everybody to use USB instead -
which although adequate for computer devices, like mice and printers,
is of no use for serious MIDI. USB suffers from a granularity of 1ms,
a high overhead for small packets and a bus shared with other devices,
hardly ideal if external clocks or timecode synchronisation are
required as well. "
"Now MegaWolf Inc. have introduced the Romulus & Remus PCI Serial Port
Cards with highly specified UARTs capable of sustaining high data
rates. No Macintosh MIDI software really uses this to the full. The
best is FreeMIDI which can achieve an accuracy between ports of within
0.5ms, tested with 8 Standard Interfaces, one per track under ProTools
5LE. OMS comes a poor second, dropping to 1ms with only two Standard
"Note that this interface only works with Romulus/Remus serial ports
and not the normal Macintosh Printer or Modem ports as they require a
clock to be provided as well. Also, the maximum combined length of the
serial cable and any attached MIDI cables should not exceed 15 metres.
Longer runs can be achieved by reducing the two resistor values down
to a minimum of 270 ohms, but do not reduce by more than necessary as
you will be driving more current through the MIDI In circuitry of your
The simple cable referred to in the last quote above requires an
add-on serial card? That's what it says, I think?
The questioner was hoping to be able to get midi bt attaching a simple
cable to a standard Mac port. I see nothing on the site to suggest
this is possible.