Help connecting an old Model M

s0b

21 Aug 2014, 17:22

Im having problems to connect my IBM Model M 1386303. It comes with a DIN 5 connector like this one:

Image

Some months ago I bought two adapters to connect this keyboard to my computer but I failed miserably because this keyboard uses a different 5 pin connector. These are the two adaptors:

5 pin to PS2: http://www.amazon.co.uk/gp/product/B002SI9EDQ <-- Fail!
PS2 to USB: http://www.amazon.co.uk/dp/B001NYDMSO

What I need to connect that type of DIN 5 connector to ps2 or USB?

Thanks!

User avatar
Halvar

21 Aug 2014, 18:08

This isn't a PC keyboard, it's a terminal keyboard for a mainframe computer terminal. Which means that not only the pins on the connector are different, but also the communication between keyboard and computer. A passive adapter to PS/2 or a standard adapter to USB will not work.

User Soarer from this forum built/wrote a converter for terminal keyboards <-> USB.

Here's the thread:
http://deskthority.net/workshop-f7/xt-a ... t2510.html

Soarer has an extensive documentation in the download that tells you how you can build one.

It's easier than you might think, but some light soldering is required.
Basically the steps are:
1) find and buy a DIN connector that you can plug your cable in
2) order a "Teensy", a little microcontroller board with lots of solder connectors and a MicroMini-USB port (costs about 15-20 €) and a MicroMini-USB cable
3) solder four cables from your DIN connector to the Teensy
4) connect the Teensy to your computer and use the teensy software to flash Soarer's software onto the teensy.
Done.

Optional steps:
5) build a nice housing for the converter
6) program your keyboard with macros, a custom layout or whatever you please with a configuration file for Soarer's software
7) solder LEDs to the Teensy for CapsLock/ScrollLock/NumLock

This is basically how it could look:
Image
Last edited by Halvar on 21 Aug 2014, 18:44, edited 1 time in total.

User avatar
Muirium
µ

21 Aug 2014, 18:40

Halvar's right. (But it's a mini USB cable you need. Soarer's only works with Teensy 2, not Teensy 3.)

You can build the converter inside your keyboard if you like. The Teensy is indeed tiny.

User avatar
Halvar

21 Aug 2014, 18:45

Muirium wrote: Halvar's right. (But it's a mini USB cable you need. Soarer's only works with Teensy 2, not Teensy 3.)
That's right, sorry. Edited it in.

User avatar
Halvar

22 Aug 2014, 11:17

If you don't want to solder, an alternative could be to find the controller and PS/2 cable of a standard PC Model M and use that. There's a small risk that it doesn't work though. I'm quite confident that the keyboard will have the same internal membrane connectors and matrix as a standard PC Model M, but you can't be 100% sure.

I did that with my terminal Model M SSK and it worked without a problem, even though I used the controller of a fullsize Model M in an SSK.

For that you wouldn't need to solder, just open the keyboard and exchange the controller pcb. The controllers and cables are sometimes sold on ebay, but you could ask here in the marketplace, too.

What you would lose is the extra key on the num pad -- it will probably do nothing with a standard PC controller.

The Soarer converter is the better solution IMO -- you don't need to modify your keyboard at all, and it's even freely programmable with the converter.

ShawnMeg

30 Aug 2014, 03:10

Mr. Interface has a great tutorial on youtube. All the soldering he did was tinning the wires. He plugged the tinned wires into a solderless breadboard. Rather than a converter box, he put electrical tape around the hold apparatus. Kind of ghetto, but it looked pretty easy. I'm in the process of doing this. I'm ordering parts, and will try the minimal soldering technique. There may a completely solderless solution, like maybe using jumper wires.

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