gdjacobs wrote:

Advantage is fully isolated ground.

You can't optoisolate the output because it needs power from somewhere. Ok you could use batteries.

But it already is fully isolated because every device has an opto isolated input.

Sorry, brain malfunction. I was thinking of the MIDI in. I'd likely build both in and out on any adapter I made.

FWIW, you could use 74LS02 or 74LS04 chips with minimal changes if you've got some kicking around. All depends what you've got for bubble gum logic.

I almost made that cable, even found one little brown ceremic cap, which have 104 written on it, correct? But now I got little confused, because my 5 Pin Din male from old AT keyboard has vice versa numbering then the last page shcematic? Pinout from the OUTSIDE view looks like male in this picture: http://www.horrorseek.com/home/halloween/wolf … DIN5-pinout.gif

I assuum that schematic picture 5 Pin Din is "looked from inside/solderable view"?

Which way from this view http://kumanosu.jp/eBay_img/MU50/5447/rear.jpg is Txd and +5V in that MIDI IN from the middle (GND)? If I connect now, +5V would go one to the right from the middle and Txd would go one to the left from the middle.

Should I change 4 & 5 other way?

Any help/advice?

The pinout written in the conector should be right - just follow the numbering.

Thanks, I kind of figure out myself a while ago with these pictures http://r-massive.cellarseer.com/wp-content/up … _cable_pins.jpg & https://www.pjrc.com/teensy/td_libs_MIDI_2.jpg , I assuum I have done it right, nothing burned 😁

Now, how setup MU50 work with those older games? Any guide? I assuum that host switch should be in MIDI position?

In DOS you just set the games up to use General MIDI through the MPU-401 interface. It should just work. If you are using Windows, though, depending on the driver it could be redirecting it to some software synth. Go to the Control Panel and find you sound card's setup utility (or its setup utility in the start menu). If there is no such things, just set the external MPU-401 interface as the default MIDI device (in the multimedia applet), and this should be enough.

Hi guys,
(didn't want to create a new thread)

is it possible to create a DB-15 to MIDI cable without using the photocoupler and resistors?
I have a Yamaha Waveforce WF192GX and would I be wrong to think the DB-15 port already has these things implemented on the MIDI section on the PCB?

Has anyone used a completely passive DB-15 MIDI cable? (i.e. no hot-swapping?)

hageir wrote:

Hi guys, (didn't want to create a new thread) […]
Show full quote

Hi guys,
(didn't want to create a new thread)

is it possible to create a DB-15 to MIDI cable without using the photocoupler and resistors?
I have a Yamaha Waveforce WF192GX and would I be wrong to think the DB-15 port already has these things implemented on the MIDI section on the PCB?

Has anyone used a completely passive DB-15 MIDI cable? (i.e. no hot-swapping?)

Yes, it's possible but very risky. You really need opto isolators in these cables (on midi input) otherwise you risk problems with the ground loop or even damaging your equipment if the controller runs on some weird voltage. Not to mention it's not what MIDI specification calls for: http://www.midi.org/techspecs/electrispec.php

Short answer: don't do it if you care for your equipment.

HanJammer wrote:

hageir wrote:

Hi guys, (didn't want to create a new thread) […]
Show full quote

Hi guys,
(didn't want to create a new thread)

is it possible to create a DB-15 to MIDI cable without using the photocoupler and resistors?
I have a Yamaha Waveforce WF192GX and would I be wrong to think the DB-15 port already has these things implemented on the MIDI section on the PCB?

Has anyone used a completely passive DB-15 MIDI cable? (i.e. no hot-swapping?)

Yes, it's possible but very risky. You really need opto isolators in these cables (on midi input) otherwise you risk problems with the ground loop or even damaging your equipment if the controller runs on some weird voltage. Not to mention it's not what MIDI specification calls for: http://www.midi.org/techspecs/electrispec.php

Short answer: don't do it if you care for your equipment.

Alrighty, thanks for the answer, my dude.
I'll grab those parts, no stress 😀 Better to be safe than sorry.

Over & out,

-G