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geekhack Projects => Making Stuff Together! => Topic started by: E_Davion on Mon, 28 December 2015, 23:32:33

Title: Question about wiring RJ45-->PS/2
Post by: E_Davion on Mon, 28 December 2015, 23:32:33
Hello,

I have recently come across a lovely IBM Model M 1395162 with an RJ45 output.  I read through a lot of tutorials and overviews and have Soarer's converter being shipped as I type this.  Unfortunately the RJ45---->USB sold out a day before I started looking so after a little reading I decided I could manage wiring the RJ45 into a PS/2 cable and went and purchased the last PS/2---->USB converter available where I was looking.  The converter supposedly will handle all 'translations' required to get this baby compatible with my PC.

In doing the wiring I ran into a small problem.  With the use of some electrical tape and parts/pins from an old router I have created pins branching out from the RJ45 connector at the end of the Model M without much issue.  The problem lies with the other half of this equation.  I had an old Microsoft PS/2 keyboard lying around which I have cut the wire from and taken an inch or so off the coating.  I have revealed an apparently unorthodox color scheme which leaves me hesitant to guess which wire corresponds to ground/data/clock and +5V.

Is anybody familiar enough with Microsoft keyboards to help sort out the colors?  The model of the keyboard is Microsoft Internet Keyboard and the part number is X08-74735.  I have included an image of the wires I am looking at.  I have pinout diagrams however I have about 2 feet of cable to work with and I honestly have no idea how I would trace the pins to the corresponding wires through that much cable.  I was hoping to make use of the length to give more breathing room when everything is finally together.  Thank you very much for your help.

(http://s22.postimg.org/j72l618m5/MS_Wires.jpg) (http://postimg.org/image/j72l618m5/)
Title: Re: Question about wiring RJ45-->PS/2
Post by: rowdy on Tue, 29 December 2015, 01:12:15
Welcome to Geekhack!

Your best bet would be to get a multimeter and test each wire.

I managed to do that when fabricating a replacement PS/2 cable for a different model Model M keyboard - works well, although mine was PC-compatible in the first place, just that someone had cut the original cable off.
Title: Re: Question about wiring RJ45-->PS/2
Post by: E_Davion on Tue, 29 December 2015, 13:47:03
Thank you.  The funny thing is I have a multimeter lying around and for some reason it hadn't even occurred to me to use it in that manner.  I've typically just been using it to check batteries and outlets around the house when need be.
Title: Re: Question about wiring RJ45-->PS/2
Post by: Snowdog993 on Tue, 29 December 2015, 13:49:47
Hello,

I have recently come across a lovely IBM Model M 1395162 with an RJ45 output.  I read through a lot of tutorials and overviews and have Soarer's converter being shipped as I type this.  Unfortunately the RJ45---->USB sold out a day before I started looking so after a little reading I decided I could manage wiring the RJ45 into a PS/2 cable and went and purchased the last PS/2---->USB converter available where I was looking.  The converter supposedly will handle all 'translations' required to get this baby compatible with my PC.

In doing the wiring I ran into a small problem.  With the use of some electrical tape and parts/pins from an old router I have created pins branching out from the RJ45 connector at the end of the Model M without much issue.  The problem lies with the other half of this equation.  I had an old Microsoft PS/2 keyboard lying around which I have cut the wire from and taken an inch or so off the coating.  I have revealed an apparently unorthodox color scheme which leaves me hesitant to guess which wire corresponds to ground/data/clock and +5V.

Is anybody familiar enough with Microsoft keyboards to help sort out the colors?  The model of the keyboard is Microsoft Internet Keyboard and the part number is X08-74735.  I have included an image of the wires I am looking at.  I have pinout diagrams however I have about 2 feet of cable to work with and I honestly have no idea how I would trace the pins to the corresponding wires through that much cable.  I was hoping to make use of the length to give more breathing room when everything is finally together.  Thank you very much for your help.

(http://s22.postimg.org/j72l618m5/MS_Wires.jpg) (http://postimg.org/image/j72l618m5/)

It's not going to work that way.  The controller speaks one language and the adapter another.
(That's the easy way of explaining this.)
Do this instead:
Remove the terminal controller and replace it with a standard 1391401 SDL controller.

http://imgur.com/a/iNjFR

Edit: Unless you want to do a Teensy Mod.  That is an entirely different story.
Title: Re: Question about wiring RJ45-->PS/2
Post by: E_Davion on Sat, 02 January 2016, 03:10:55
Quote
It's not going to work that way.  The controller speaks one language and the adapter another.
(That's the easy way of explaining this.)
Do this instead:
Remove the terminal controller and replace it with a standard 1391401 SDL controller.

http://imgur.com/a/iNjFR

Edit: Unless you want to do a Teensy Mod.  That is an entirely different story.

Well I was hoping to go about this in the same route as was suggested by dfj in a similar thread a few years ago. https://geekhack.org/index.php?topic=10737.0 (https://geekhack.org/index.php?topic=10737.0)  A few people posted in that thread that following that strategy worked for them.  Since I didn't want to cut the end of the keyboard's RJ45 unless I absolutely had to I am leaning towards picking up an RJ45 Breakout board and then plugging the keyboard into it and wiring it into a detached PS/2 cable which will then either go straight to my PC or into Soarer's mod and then into my computer.  I've heard mixed reports that for some keyboards the converter isn't required for basic functionality but I'll probably use it even if I don't need to just for the added features like NKRO.

I have looked at a few places online and cannot seem to find any currently available SDL controllers so for the time being I'm stuck with my current one.

I am also keeping in the air the possibility of just opening it up and swapping to a PS/2 cable as a whole.  This would require me to get a 5.5mm nut driver though as my current set of tools won't fit down those little holes in the back.
Title: Re: Question about wiring RJ45-->PS/2
Post by: fohat.digs on Sat, 02 January 2016, 08:45:00
Orihalcon's cables are the easiest way, and he will surely make more, although probably not today.

The Soarer's/Teensy route is easy enough but it looks like you are deep into it already. A multimeter tracing back from the PS/2 pins will easily identify the wires.
Title: Re: Question about wiring RJ45-->PS/2
Post by: SamirD on Sat, 02 January 2016, 09:27:26
An easy way to find out which wires are corresponding to which pins (bsides using the multimeter) may be to just strip away a little of the outside insulation near the ps2 plug.  You should be able to figure out which wires correspond to what after that.