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CharlieFrown

Lost Mac Plus keyboard cord

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10 minutes ago, Gorgonops said:

Seriously, there's no defense for suggesting people try this for laughs *and* that quote from the Apple "engineer" is just gobbledygook. Telephone cables work if you cut the end off and flip the pinout, Dog Cow said that himself, for sheesh's sake! 

Yes, exactly. It's so easy to do it right that there isn't any justification for trying the wrong way just to see what happens. Applying power backwards to semiconductors rarely results in a happy outcome...

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12 minutes ago, Gorgonops said:

*and* that quote from the Apple "engineer" is just gobbledygook.

I am more surprised you dont know who his is.

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6 minutes ago, unity said:

I am more surprised you dont know who his is.


I had to remind myself, and... am I supposed to be impressed? Apparently he was a music major in college that got his job at Apple because Steve Jobs liked doing LSD with him. He may well have learned enough ad-hoc electronic knowledge in the trenches to put together various digital tinkertoys, but there's a lot of room there to suspect that his word shouldn't be considered even remotely like gospel on a matter like this. Not to mention the fact that he may well just have been talking out of his *** when he was quoted in that magazine article because he didn't actually *remember* why it was a bad idea to use a telephone cord for the keyboard. He may well have had nothing to do with the final decision of how the connectors were laid out.

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Well he helped design the original Macintosh keyboard. So there is that.

 

Dont get me wrong, I am not saying he is right or wrong. I dont have the schematics handy to actually look. But is was more than just an LSD using buddy of Jobs, he did a lot of board level work. So I would not dismiss him so easily.

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I'm not saying he didn't have any talent, but nonetheless his job title at Apple for a *long* time was "technician", not "engineer". He did take some extension courses and managed to convince Apple to upgrade his job title so he could say this:

 

Quote

"On the Macintosh, I was the one who did the keyboard, which was a single-chip computer, a computer subsystem. That was my first embedded system project."

 

But... really, this discussion isn't about how good of an engineer Dan was or was not, it's whether that statement makes any sense, and clearly it doesn't. Applying reverse voltage to TTL/CMOS electronics is a demonstrably bad thing, and the keyboard pinout of the Mac isn't a mystery, that is what you're doing when you use a telephone handset cable in place of the Apple one. I have personally destroyed electronic devices by plugging universal power supplies set to the incorrect polarity into them, so unless they *specifically* included protection against that eventuality in the keyboard it is indeed nothing but luck that would let you survive doing it.

I will throw this out there, just for laughs: I kind of wonder if Dog Cow might have plugged in a *2* conductor RJ-11 cable instead of a 4 conductor cable when his mac survived it. If you only connected the center two pins reversed then, sure, that probably wouldn't hurt anything since you'd only be crossing the data and clock wires while leaving the keyboard unpowered. I just checked the POTS telephone on my desk and, yes, its handset cord has only 2 conductors. Quite a few phones do.

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You might be right about the two pin. If I recall, most headsets only used two wires anyway. They did not the the ringer wire.

 

edit: nevermind, that would not make sense. Still need at least a third for ground.

Edited by unity

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The phone I looked at was one with the dial in the handset. My guess is that the base has essentially nothing in it and is just passing tip and ring from the wall through it, thus only needing two wires.

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