grossman@Sunburn.Stanford.EDU (Stu Grossman) (07/19/90)
I am looking for a gadget that will convert between RS232 and MIDI signal levels. I want to use this to connect the serial port on a SUN workstation to some MIDI instruments. Has anybody out there heard of such a creature? As I understand it, MIDI runs at 31250 baud, and uses 10 bit frames with eight data bits, one start and one stop bit. So far, no problem. I can program the Sun to deal with all of that stuff. The hard part is that MIDI signaling is 1.5 milliamp current loop (balanced or unbalanced?). If there is a ready-made product for this purpose (at a reasonable price), I will gladly buy it. I've checked out some of the interfaces for Macs and PCs. The Mac interface that I saw seems to take power from the Mac, and did not come with a pinout diagram. I don't think that I can get the appropriate power out of the Sun's serial port, so that means that I would have to get a power supply and hook it up to the correct pins. The PC interfaces that I've seen use plug-in PC boards, which are pretty much useless for me (unless I had a Sun-386i (which I don't)). I've haven't been able to look at the interfaces for the Amiga, perhaps one of them might work? I'm willing build the interface if I can get hold of an appropriate schematic. I don't have any knowledge of electronic circuit design, so the schematic had better not require any (serious) hacking. Thanks in advance! Stu Grossman
billq@ms.uky.edu (Billy Quinn) (07/19/90)
I saw an add in this months Electronic Musician magazine, for a company called Key electronics (?). They sell an RS232 - MIDI interface and send source code too. If you don't have this magazine handy send me personal mail (billq@s.ms.uky.edu) and I can get you the address and phone number etc. --
tjt@cbnewsh.att.com (timothy.j.thompson) (07/19/90)
From article <1990Jul19.012554.7985@Neon.Stanford.EDU>, by grossman@Sunburn.Stanford.EDU (Stu Grossman): > I am looking for a gadget that will convert between RS232 and MIDI signal > levels. I want to use this to connect the serial port on a SUN workstation to > some MIDI instruments. Has anybody out there heard of such a creature? Key Electronics has an RS232 to MIDI interface that (they say) will work with any computer. It's basically just a baud-rate converter (works from 300 to 38.4Kbaud), they do *no* buffering or timestamping. It does, however, have 4 MIDI outs that are selectable by switches or, apparently, by using the modem control lines, so you can do multiplexing. It costs $229.95. Contact Key Electronics, 1-800-533-MIDI. I have no personal experience with the interface, I've just read the glossy. ...Tim Thompson...tjt@twitch.att.com...
mbonder@rodan.acs.syr.edu (Mark Bonder) (07/20/90)
In article <1990Jul19.012554.7985@Neon.Stanford.EDU> grossman@Sunburn.Stanford.EDU (Stu Grossman) writes: >I am looking for a gadget that will convert between RS232 and MIDI signal >levels. I want to use this to connect the serial port on a SUN workstation to >some MIDI instruments. Has anybody out there heard of such a creature? >(lots of stuff deleted) > Stu Grossman I use something called the ECE MIDI. It plugs into the serial port of my Amiga, has a serial port on it, and also MIDI in, out, and thru. Finally it has a pushbutton switch to toggle between MIDI and RS-232. Works great for me. It's by ECE Research & Development Corp. 1651 N Monroe St. Tallahassee Fla. 32302. Phone (904)681-0786. hope this helps.. - Mark
dhj@rhun.watson.ibm.com (David Jameson) (07/20/90)
Be careful. The interface made by Key electronics makes assumptions about the serial interface. In particular, there's something about the RS-232 on a PC that lets it work but it's not guaranteed to work on any other machine. Check with them first. David Jameson T.J. Watson Research Center Yorktown Heights, NY 10598 (914) 945-2681 dhj@rhun.watson.ibm.com
tjt@cbnewsh.att.com (timothy.j.thompson) (07/21/90)
From article <1990Jul20.144223.9123@arnor.uucp>, by dhj@rhun.watson.ibm.com (David Jameson): > Be careful. The interface made by Key electronics makes assumptions > about the serial interface. In particular, there's something about the > RS-232 on a PC that lets it work but it's not guaranteed to work > on any other machine. Check with them first. That was true of their original product, but they now have one that is supposed to work with any computer's RS-232 interface. ...Tim...
rich@sendai.sendai.ann-arbor.mi.us (K. Richard Magill) (07/22/90)
In article <1990Jul19.012554.7985@Neon.Stanford.EDU> grossman@Sunburn.Stanford.EDU (Stu Grossman) writes:
I am looking for a gadget that will convert between RS232 and MIDI signal
levels. I want to use this to connect the serial port on a SUN workstation to
some MIDI instruments. Has anybody out there heard of such a creature?
Yes, but. I've had some luck with putting an amiga interface, (check
the pinouts before buying, there are several types that use amiga only
signals), and hacking the speed table in the tty device driver. I
haven't spent much time on this yet so I'm not real sure how solid it
really is. My goal was to build a streams device driver over midi but
other things like an impending wedding are eating my time instead.
The doc that comes with Tim Thompson's Keynote (from the at&t
toolchest) mentions another serial to midi device but I know nothing
else about it.