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Wired USB Apple Keyboard Hack


Mr.D.
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I don't have this keyboard - mostly because I am cheap. If anyone wants to donate to the "Mr.D. wants an Apple Keyboard Fund", PM me.

 

Regardless, this is a very cool hack, and it works for non-Apple USB keyboards with bus powered hubs. I have an older Dell USB keyboard with a 2 port hub. Also, in the comments for this video, someone remarked that they searched by Hardware ID rather than Location Information. I found two instances in my registry and only the one that I found using the Hardware ID was the correct one.

 

This is a very good video and a very good list of comments related to it - Wanted to share! Hope this helps some people.

 

http://www.youtube.com/watch?v=s8kVWy8Qf7A

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  • 2 weeks later...

Interesting... As an owner of Apple Aluminium Wired KB, I can confirm the problem. However I'd rather use an external USB hub or hub in an external display (I do in fact).Just to be on the safe side.

 

IMO this build in USB hub is intended for devices like USB mouse (quite convenient) or similar low power device.

 

@Mr.D

How about "Mr.D. wants a New Mac Pro Fund"? :)

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now THAT is an outstanding idea! I take it you'll be the first donator?

 

I can find them used - hell, there is one just taunting me at the pawn shop 3 blocks from my house - but I got my Dell keyboard for free, and it has a volume knob and everything! can't beat free. AND this trick works just fine on my Dell keyboard too.

 

Regarding safety, amps (miliamps in this case) or current is pulled from the source. Bumping the spec up in a registry hack doesn't change how much is pushed to the device (that would be volts), just what is available for the total at the end plug. Think of it like this - you have a circuit breaker box in your house that has a 15 amp current limit. You plug in a 120v toaster that pulls 200w, assuming your PowerFactor is max at 1 (amps = watts / (PF × volts)) means you are pulling .6 amps of the available 15 amps. You could plug in 25 toasters to that circuit before you popped it. But what if you need to run 33 toasters?? You can replace the circuit breaker in the box to a 20 amp, with 33 toasters pulling 19.8 amps, you's still be OK. But what about the total load on the system? In this analogy, you CPU power supply is the main feed coming in from the house. A lot of older residences are sourced for 100-125 amp service. A lot of newer houses are sourced for 200 amp service. Replacing one circuit breaker with a bigger one in the box isn't going to overload your entire system - replacing ALL of them probably will, and you'd need more available amps from the power company (i.e. changing the power supply in your computer). Changing the available amps to your USB keyboard from 100ma to 500ma, giving a total available of 1000ma, plus the draw from the keyboard (lets estimate a max of 500ma) bringing up the total to 1.5 amps - which is within the specs that I have been able to Google just now (anywhere from 1.5a to 1.8a to 2.25a for HighSpeed USB 2.0, not pulled from Wikipedia, which has contradictory information in the same posting - UGH). My sources are here, here, here, here, here, and here. Of course, this is ALL dependent upon what your motherboard manufacture decided to do. If you have USB 3.0, it really shouldn't be an issue. USB 2.0 might be hit or miss depending upon the manufacture of the board and the age. If all you have is a USB 1.1 motherboard, stop reading now. Seriously.

 

If you'll excuse me, I have a lot of toast to eat...

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now THAT is an outstanding idea! I take it you'll be the first donator?
Sure! as soon as I get one or two for free :)
If you'll excuse me, I have a lot of toast to eat...
bon appétit! :)

 

As for Amps, Volts and such... I'm a designer, electronics are not my strongest point. At all.

 

AFAIK not only capacity of the source matters, but also the circuit that transports the power between the source and the end device. I don't know how the PCB in the keyboard is designed, so can't say will the circuit be able to handle 1.5 or more (the wire that connects the keyboard to USB IMO is quite thin). Nor I know how the MB in my notebook is designed (it may not hold that much). ESP if there are only two working USB ports left in the notebook...

 

P.S. Found an interesting info related to the subject

http://community.wdc.com/t5/WD-Portable-Drives/How-to-eliminate-potential-problems-on-USB-Powered-Drives-and/m-p/118262/highlight/false#M3760

Each USB port is capable of delivering 500mA @ 5Volts max and each port has built in semiconductor fuse that disconnects when external device power drain exceeds rated power output. This fuse will heal itself once the offending device disconnects. This fuse inherits tolerance of 5-10% of 500mA plus or minus. That means it could be disconnecting either on 450mA or 550mA of current drain.

 

Most of the newer desktop PC’s equipped with 1Amp (1000mA) self-healing fuse; so drawing more than 500mA from a port may not be an issue. Please note that this 1Amp fuse in motherboard may be shared to several ports so connecting multiple USB powered (Drives) devices simultaneously could still could be leading to power starvation on drives. Low power devices (Pen drives etc.) may not exhibit this problem.

Edited by 3.14r2
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