Caught on tape by an undercover CIA agent were Sundeep Goel's words:
 SG> I have just bought a Yamaha PSR 320 and I want to connect it to the
 SG> sound card in my computer.
 SG> I am not able to get the required cable here. So, have decided to
 SG> build one myself, could someone please tell me the wiring diagram for
 SG> the cable from the joystick / midi port on the sound card to the midi
 SG> in / out ports on the Yamaha.
    I don't know if the Yamaha's joystick port is wired exactly like the
 Sound Blaster, nor if it even channels the MIDI through the joystick
 port.  But, you asked, and here are several sets of schematics I found
 on the interenet.  I built a version of one of them, just because I
 like doing thatkind of thing, and it works fine.  The main hassle was
 figuring out how to configure the SB card to turn on the joystick
 port's MIDI out feature.
    This is several different messages with slightly different plans and
 parts, but I include them all because each one has better, more clear
 info about one aspect of the hardware than the others.
    Because these are some looong files, I'll split them into about five
 different messages.
 ----------------------------------------------------------------------
 From: hardrock@underg.UUCP (hard rock)
 Subject: Sound Blaster MIDI port
 Date: 18 Feb 92 21:12:52 GMT
 I have downloaded a program called CHEAPMID.ZIP, I found it on Point of no
 return.  I was just wondering if anyone else have tried to project.  It is
 suppose to make the interface required to connect midi equipment to the
 sound blaster.  Also when I went to buy the equipment, I could only find the
 8 pin chip for the midi, and it talked about a 6 bit chip.  Well here is the
 text for those who are interested.  BTW, I haven't tried this out yet, I
 have created the model, but need some equipment to test it on.
 ---
 The following text explains how to build a MIDI interface for the
 Sound Blaster. The circuit is my own design, but works just like
 the commercialy available interfaces that retails for $60-$90.
 
 Here is the list of parts necessary:
 
 Qty.           Part
  1    Sharp PC900 or HP 6N138 opto-isolator
  1    DB15P (15 pin 'D' connector, male. like joystick connector)
  3    220 ohm resistors (2 for input, 1 for EACH output you need)
  1    3 conductor shielded cable (length is up to you)
  2    Female 5 pin DIN connector (1 for input, 1 for each output you need)
  1    PC board with pre-drilled holes (about 2" x 2" from Radio Shack)
       A few short lengths of hook-up wire
 All of these parts, except the first 2, are available from Radio Shack.
 Construction techniques are completely up to you, if you want to go
 ultra-cheap, you don't even need a PC board or enclosure, and you could
 use a MIDI cable you already have by cutting it in the middle. I used
 a PC900 out of a non-working organ and cut the end off of a joystick I
 didn't need and built the whole thing for about $4.00. Buying all the
 parts new, and using an enclosure with built-in MIDI jacks may cost
 about $20 or so.
 Here is a diagram of the DB15P connector (looking at the solder side).
     1       5     8
     o o o o o o o o
      o o o o o o o
      9     12     15
 Here is the 5 pin FEMALE DIN plug (solder side).
        2
    5   o   4
      o   o
   3  o   o  1
... Balance the thoughts that release within you.
--- PPoint 2.06
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