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Need a pinout for this Thinkpad MIDI port

xjas

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Jul 9, 2015
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So I have this lovely little Thinkpad 365ED with a built-in ISA ESS Audiodrive & a real MIDI port on the back. Unfortunately this being '90s IBM it uses a proprietary mini-mini-D-sub-thing that I've never seen anywhere else.

thinkpad-midi-1.jpg

thinkpad-midi-2.jpg
It's the port on the upper right. Just 1cm wide! The one below it is for the external floppy drive.

There is an official gameport/MIDI port cable for this which adapts it to a standard DB15. The IBM part # is 75H7576. There are currently none on Ebay, but several creaky looking "thinkpad-parts-online!" type websites claim to have them in stock and might sell me one for $30 US. Plus another $25 for shipping (UPS only, of course) and who knows what in 'brokerage' & taxes. *IF* they even have them, and *if* they are the right cables as there are apparently different ones for different Thinkpads, and *if* they don't accidentally send me the wrong one & give me no recourse to return it when it arrives and doesn't work. Then I *might* be able to have one for approx. $75+ in my money when it finally gets here. Meh.

So naturally I'd rather build my own. Was this little connector used in anything else? Anyone have a likely source for me?

Even if I had just the pinout I could hack something together with a ribbon cable. Any info is appreciated.
 
At first glance i thought it would be like these Tidalwave palmtop Serial cables, but i count 14 pins on your midi interface, right? These tidalwave only had 10 pins, but the shape looks extremely similar. But probably an IBM special. I'd try hunting down all service manual PDFs and stuff you can find, usually IBM is pretty good at describing their stuff.


Some seller list part 75H7576 as a "Game port" cable, make sure it is really a midi cable and not just for a joystick before you try hunting that down. Triple check the manual and everything.
 
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Yeah, 14 pins (7 top, 7 bottom.) Given that it adapts to a 15 pin D-sub I'm willing to bet it's just a 1:1 cable with one of the (many) unused pins left off.

100% sure the standard IBM cable connects the MIDI pins; it's referred to in the manuals and on thinkwiki.org as a "gameport/MIDI cable." If there are aftermarket ones floating around out there then who knows.

It's a really narrow little connector too. Like, I can barely even get a multimeter probe in there without touching more than one lead at a time. Makes reverse engineering it a bit difficult. I'd be happy to open it up and retrofit a standard DB15 if I thought one would fit without it being a complete hack job, but it definitely would. :p And this thing is *annoying* to get apart.
 
Yeah, 14 pins (7 top, 7 bottom.) Given that it adapts to a 15 pin D-sub I'm willing to bet it's just a 1:1 cable with one of the (many) unused pins left off.

100% sure the standard IBM cable connects the MIDI pins; it's referred to in the manuals and on thinkwiki.org as a "gameport/MIDI cable." If there are aftermarket ones floating around out there then who knows.

It's a really narrow little connector too. Like, I can barely even get a multimeter probe in there without touching more than one lead at a time. Makes reverse engineering it a bit difficult. I'd be happy to open it up and retrofit a standard DB15 if I thought one would fit without it being a complete hack job, but it definitely would. :p And this thing is *annoying* to get apart.

Not so sure about that. The standard SoundBlaster gameport MIDI adaptor has the Opto Isolators in the socket....
 
The cable I'm after converts my mini-D-sub-thing to a standard DB15, the MIDI cable with the optocouplers plugs in after that. I'm not aware of a direct Thinkpad port->MIDI DIN5 cable for this machine.
 
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