🚀 go-pugleaf

dillon@overload.Berkeley.CA.US (Matthew Dillon) writes:

>>In article <1992Oct8.025357.9551@cube.handheld.com> jmd@cube.handheld.com (Jim De Arras) writes:
>>>In article <1ask66INN2ga@ustores.ustores.missouri.edu>
>>
>>I would NEVER put the battery in backwards!  If they have a protection diode,
>>it will do nothing.  If not, you run the risk of damaging the clock chip, or of
>>exploding caps or even (remotely) blowing the battery seals!

>    If the battery is connected directly to the RTC chip then you are
>    definitely forward biasing the static discharge diodes internal to the
>    device, about 50 ohms per pin (in parallel) if you reverse the battery.
>    This would destroy the RTC chip rather quickly.

>    if there is a protection diode across the batterly leads (and not
>    inline) to protect the RTC chip, the battery will be shorted and can,
>    literally, explode.

>    On the otherhand, if NeXT has inserted a diode in series with the
>    battery, then nothing will happen at all because the diode will be
>    reverse biased.

>    I don't know what RTC chip the NeXT is using.  Most RTC chips, like the
>    ones from Dallas Semiconductor, draw picoamps (on the order of 300pA or
>    less).  Therefore, the bypass capacitors alone would be able to retain
>    enough voltage to run the RTC for several minutes.	The best solution
>    is to take out the battery and short the battery terminals on the
>    motherboard together for a second or two to discharge the bypass
>    capacitors.

>    NOTE:  I HAVE NOT TRIED THIS MYSELF but it's certainly safer then
>    putting the battery in backwards!

>					-Matt

>>> --
>>> Bill Canning 		usbill@ustores.ustores.missouri.edu (Internet)
>>> (314) 882-2131			muccgw.usbill@ssgate.missouri.edu
>>(cc:Mail)
>>> [314] 882=4699 (Fax) 	CSPECWC@MIZZOU1 (BITNET)
>>
>>Jim
>>
>>--
>>Jim De Arras		 | The opinions expressed herein are
>>Hand Held Products, Inc.| not necessarily those of Hand
>>804.784.3090 voice	 | Held Products, Inc., and may not
>>804.784.3147 FAX	 | even be mine. Use at your own risk

>--

>    Matthew Dillon		dillon@Overload.Berkeley.CA.US
>    1005 Apollo Way		uunet.uu.net!overload!dillon
>    Incline Village, NV. 89451	ham: KC6LVW (no mail drop)
>    USA 			Sandel-Avery Engineering (702)831-8000

The best suggestion is to use HardwarePassword.app by eps and not
stuff around with batteries and the like.