Owners of applicable Model M keyboards will be aware that their keyboard cable is detachable from their keyboard. The type of plug and socket used for this connection, apparently because IBM favoured AMP for connectors, is called
SDL (for Shielded Data Link) and in this application is the 6 pin version.
Male SDL plugs are assembled out of small pieces that make up the overall connector once crimped together. IBM, however, seemed to skip one part of the assembly: the
plug boot (Tyco P/N 520852-1)!
Now, you may ask, what is a plug boot? Take a look at a typical ethernet cable...see the rubber housing around the plug which protects the lock tab? That's a plug boot.
Random internet example.
Here's an SDL plug boot:
These are the proper Tyco/AMP parts which are a proper match for most of our Model M cables. The proper way to install them is to put them on the cable before attaching the connector, but I'm going to show you a ghetto-fabulous way to get this effect:
There are different types of plug used for Model M cables. I'll go through them later in the article. Here's all you need to know for now, though:
Best type, definitely works:
Results using that plug:
As you can see, there's a split in the bottom of the boot. This relates to the...
Installation Method:Simple.
1) Use utility knife to make a more or less straight cut lengthwise along the connector (do not cut in half! only split one side). I recommend you go with the "bottom" side for cosmetic reasons.
2) Lightly spread boot, but not too much. It's mostly firm plastic and won't go back easily if pushed too far.
3) Get cord through the split. Do this a bit down from the connector.
4) Slide boot up onto connector. It should roughly match the results I showed a bit higher up.
Use some sort of decent adhesive if you want to get a really snug permanent fit. I haven't and won't do that because I dislike mods that can't be undone, but there's no reason not to do it if you want to try to perfect the appearance.
If it's staying too far split out and interfering with the lock tabs, chances are you're doing this with one of the bad plug types.
Other Plug Types:Based exclusively on the SDL cables I have floating around, I've determined a few variations happened in the life of SDL plugs. In addition to the 'best' type I indicated above, we have a couple others.
Above we see what happens when there's a bad fit. The boot stretches out and impedes the operation of the lock tabs. Not good. Also not pretty.
When I refer to cable lengths, keep in mind there are 3 real lengths of PS/2 cable: "short", "medium", and "long" where the long is the gigantic like 10ft cable and medium is the more common approx 5ft one. These refer to the original coiled IBM cables only. The "best" plug type I indicated was found on a medium length cable.
Works! but not as well as aforementioned "best" type. Found this example on black genuine IBM AT cable.
Doesn't work! Found this example on the ultra long cable.
Doesn't work! Found this example on the ultra short cable.
Doesn't work! Found on what is believed to be a real IBM cable, but for some POS application. Note flat cable and different plug shape. AT end on this one.
Why the round ones have problems is beyond me. The black AT cable one works so I don't know, maybe a slightly difference in thickness? If you got creative carving out the insides of the plug boot you could make it work on even the flat cable one, my "works/doesn't work" guide is based on minimal modifications only.
Alrighty, so though it's not much of a mod, we've seen how this can improve the appearance (and to an extent ease of connection/disconnection) of these plugs. I for one happen to like what it does for the appearance.
Plug boots can be ordered online, you have the part number and are a resourceful bunch so I'll leave you to your own devices.
