Making Keyboard Cables

[bunnspecial]

I know that the early Macintosh KB cables are NOT a standard telephone cord, and using one is a guaranteed way to fry either the computer or board. I've heard the cords described as being "reversed."

I've assembled my fair share of RJ-11 cables, and generally there is a rib on one side of the cable's outer casing that allows you to keep things aligned. When assembling a "normal"(4 conductor) telephone cord, one keeps both RJ-11 connectors such that the "rib" is on the same side of both connectors.

What I'm wondering is if I put a cable together with one RJ-11 connector reversed from the the other, will I get a functional Macintosh keyboard cable?

 

[MacTech68]

In a word - NO.

The 128 to MacPlus keyboard cable should be pin to pin. That is, if you hold the connectors the same way up, the colors of the internal cables MATCH the same order on both ends.

It's actually telephone handset cables that are reversed.

Also, when buying the connectors, make sure you get 4P4C. Some handsets use 6P4C which are wider and don't fit the Mac.

 

[bunnspecial]

Thanks-I looked at a keyboard cable and a handset mounting cord, and see what you mean.

Not to argue too much, but it looks like my comment about putting the rib on opposite sides was what should be done to have the wiring correct.

Here's the original KB cable unplugged from my 512Ke

Notice that the "rib" is not on the same side of the connector, although as you said when holding the cords next to each other the colors line up.

Compare that with the handset mounting cord I had handy on my office telephone