The Mother Board

[toolfrolic]

Hi all,
my first post here.

The Mobo is operating and launching W95.
The DS12B887 RTC has died.
I want to explore the possibility of replacing the RTC, upgrading to W98 and adding a USB port.
I am in the middle of testing current generation IDE drives to see what data is reclaimable.

Identification:
Korean,
SUK JUNG ELEC,
SJ Pentium FX,
Rev c.

BIOS:
Award V4.50PG, 1995,
Triton Bios 2.10,
Plug and Play extension V1.0A,
String:
112795-110395-2A59CSCI-SJCTRITON-00

CPU:
Pentium-S 120 Mhz.

Thanks in advance for any comments and advice received.

John.

[Twisty]

Is the rtc one of the ones with an internal battery? If so then that is probably what has failed. i think it is possible to cut into the chip and solder on an external battery.
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- Webster -

[evasive]

Procedure here:
http://www.oocities.org/markuskauer/rtc.html

If you mess up, replacement chips can be bought here:
http://octopart.com/ds12c887%2B-dallas%2Bsemiconductor-998932#compare_suppliers

Adding USB ports:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007531+600022008&QksAutoSuggestion=&ShowDeactivatedMark=False&Configurator=&IsNodeId=1&Subcategory=73&description=&hisInDesc=&Ntk=&CFG=&SpeTabStoreType=&AdvancedSearch=1&srchInDesc=
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We hate rut, but we fear change.



System error, strike any user to continue...

[Karlsweldt]

That "Dallas" RTC chip design was a bad idea in several ways. Most were placed in sockets, but some were soldered to the mobo! Bad news there. But yes, it is possible to 'renew' its function with an external battery. Using a Dremel moto-tool or similar, or a dental drill, carefully burr away the area above the noted leads that are moved into the upper case area. The old battery can be left in place, but cut the leads to it.. or the battery could pop. And be cautious about excessive removal of the cover.. there likely is a crystal can in there, too!
Here is another link for a "fix".. http://www.mcamafia.de/mcapage0/dsrework.htm
And this site has a data sheet for the newer versions.. but you must subscribe to the site for the file.. http://www.maxim-ic.com/datasheet/index.mvp/id/2680
That RTC chip design was half the BIOS package.. one chip with 'odd' registers, the other with 'even' registers. Thankfully, only one BIOS chip is needed today.. and strictly an external battery!!
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F@H.. to solve mankind's maladies.. in our lifetimes!