Slicing open the top of a 48T02 Sun Sparc chip to replace b

From: jpero_at_sympatico.ca <(jpero_at_sympatico.ca)>
Date: Sun May 20 10:19:42 2001

> From: ard_at_p850ug1.demon.co.uk (Tony Duell)
> Subject: Re: Slicing open the top of a 48T02 Sun Sparc chip to replace b
> To: classiccmp_at_classiccmp.org
> Date: Sun, 20 May 2001 18:52:23 +0100 (BST)
> Reply-to: classiccmp_at_classiccmp.org

> Actually, most PC motherboards use wristwatch crystals (at least those
> where the crystal isn't hidden inside one of these Dalas (etc) chips).

Those that appeared on the motherboard after '96 or so, common
now. Chances of finding a crystal: early Pentium 30% late 80%. 486
90%. Slot 1/socket 370 95%.
 
> Wristwatches keep better time than PC motherboards for 2 main reasons.
> Firstly, there is a trimmer capacitor in the oscillator circuit of the
> wristwatch which will 'pull' the frequency a little. When was the last
> time you saw a trimmer on a PC motherboard?

Sure,
Open any 1 to 50 dollar quartz clocks and watches let it be digital
or analog. No trimmer. started around late '90's.

What happened most machines has weak batteries, accuracy go astray.
Keep your eye on that voltage. Double that watchfulness for that
machines that uses NiCd or 4 x AA, when voltage drops too much,
replace or remove them either in use or not in use, they leak and
corrodes the PCB traces. Doesn't take long to happen, few months is
enough.

> And secondly, wristwatches, at least while being worn, are kept at a
> fairly constant temperature. This improves the stability of the
> oscillator. Remmber that the frequency doesn't have to drift by very much
> for the error to be noticeable

Not all people wear it all the time, yet it keeps accurate time
especially on quartz ones.

Cheers,

Wizard - automatic watch user. Saved $35 worth of batteries,
watches I had battery has to be replaecd yearly. :-)

> -tony
Received on Sun May 20 2001 - 10:19:42 BST