George's Unit Cube of CyberSpace

Midi-in-a-D-Shell

This project has become somewhat dated. The cost of similar hardware bought off-the shelf has fallen to the point where building something is not economical.

Also, the availability of suitable serial-cards is declining, due to serial-port functions being embedded on the CPU motherboard.

Not everything is driven by simple economics, and someone may still be interested, so I'll leave this page as-is for now.

This is a Hardware Project describing how to build a MIDI adaptor for your computer. The adaptor is used to convert voltage levels, and provide electrical isolation between the components of your MIDI system.

There are two variants on the design, these being for

• a normal D25 RS232 Serial port
  
• the D15 MIDI/Games port found on most IBM-PC Sound Cards

These bitmaps are for illustration only. All diagrams and graphics are provided in PostScript format.

The D25 Serial-MIDI adaptor will work with a 9-pin serial port, when used with a normal 9-25 pin serial adaptor.

The D25 Serial-MIDI adaptor is a highly versatile, and I have successfully tested it on the following platforms:

• IBM-PC with 'doctored' serial card, running Linux OS
  (A special device driver is now available).
• Amiga (using standard hardware and software)

The D15 MIDI/Games Port adaptor will work with most IBM-PC sound cards, including the SoundBlaster and it's clones, and the Gravis Ultra Sound.

IBM-PC

For IBM-PC users who do not already have a sound card, instructions are included on how to modify a cheap (~$50) off-the shelf Serial-IO card to work at the MIDI Baud Rate, and how to configure this card on your Linux system. This serial card can then be used as a normal serial card, or as a MIDI interface when used with the D25 Serial-MIDI adaptor.

This is (ie was) actually cheaper than buying a cheap sound card just for its MIDI interface.

A custom device driver allows the D25 Serial-MIDI adaptor to be used like any other midi-port within the framework of the existing Linux sound driver.

This allows the D25 Serial-MIDI Adaptor to be used with any of the existing MIDI software for Linux

Non-Linux users who wish to use the D25 Serial-MIDI adaptor, see
http://nctnico.www.cistron.nl/midi.htm
-- or --
http://www.rolandcorp.com/downloads/driver-for-win.html

Amiga

Amiga users will be pleased to know the the D25 Serial-MIDI Adaptor works on the Amiga using the regular hardware and software.

Others

The D25 Serial-MIDI adaptor does not translate the serial baud rate to the 31250 bits/second required by MIDI. This makes it difficult to say whether or not will work on other platforms, such as Apple Macs.

Is anyone willing to try it? Let me know how you go.

First Timers

If you've never built anything before, but would like to try, I think this project is a good place to start. It's small, it's simple, and it's easy (since it all fits in the D-Shell), and the worst you are likely do is blow up the UART or CIA in your computer at a cost of around $20-$30. With this in mind. I've made instructions fairly detailed, and even included a cheap and simple method for making the PCB.

So, why not? 'Get your hands dirty !!'

All the necessary diagrams along with detailed instructions are included in the file:
http://crystal.apana.org.au/ghansper/midi/midi-in-a-D-shell-1.2.tar.gz
(103 207 bytes)
You will need 'tar' and 'gzip' to unpack it.

If you only have MS-DOS, and don't have access to these utilites, I have also created a 'zip' archive ('pkunzip' will unpack this). The files in the 'zip' archive have also been converted to use the MS-DOS CR-LF end-of-line format.
http://crystal.apana.org.au/ghansper/midi/midi-in-a-D-shell-1.2.zip
(108 548 bytes)

If you wish to archive this project on your FTP server, I suggest you take this README file as well:
http://crystal.apana.org.au/ghansper/midi/midi-in-a-D-shell.README
(938 bytes)