Looking for an old Real Time Clock Chip

[srg]

Hi

I recently from ebay won an old 486 EISA motherboard and when It arrived it had a bloody BIOS password and the EISA configuration refused not to go into the BIOS.

Anyway, the Real Time clock that was on the board was one of those large black Dallas ones (removable) and I tried to cut away the Epoxy and disconnect the battery terminal. Success, I cleared the Password. But I also broke two pins and basically ruined the chip overal so I've had to throw it away.

Anyway, does anyone know where I can get hold of a Dallas DS1387 RAMified Real Time Clock chip? Anywhere?

Maybe someone has one on and old motherboard that could be dead (the mobo that is!), or know of somewhere that does old parts.

Thanks
srg

[Candy]

You do know just about all of them have a clear-cmos jumper that clears the password?

[Eero Ränik]

There are master passwords too, as long as you know your BIOS manufacturer...

[srg]

You do know just about all of them have a clear-cmos jumper that clears the password?

This motherboard didn't have one as most Dallas RTC chips aren't Password resettable

Oh IC -- er no, this mobo doesn't have a clear CMOS jumper. And the battery was inside the RTC chip (and no, removing the chip doesn't help).

Attached is the motherbaord's entry in Total Hardware 99.

It's an old board BTW, I think from late '91 to early '92.

srg

[attachment deleted by admin]

[srg]

There are master passwords too, as long as you know your BIOS manufacturer...

BIOS is Ami, I tried all the master passwords I could find, none worked.

Anyway, the RTC chip is destroyed and I need another one.

srg

[Eero Ränik]

Google search on Dallas DS1387 gave me loads of places you can buy it from. For example, for $15, you could get it from http://www.microsalvage.com/cat50.htm, as long as you are in US.
I could look if I have it (I collect broken computer parts), but the shipping from Estonia would cost a lot.

[srg]

Google search on Dallas DS1387 gave me loads of places you can buy it from. For example, for $15, you could get it from http://www.microsalvage.com/cat50.htm, as long as you are in US.
I could look if I have it (I collect broken computer parts), but the shipping from Estonia would cost a lot.

I live in the UK

BTW I'm not sure where Estonia is, but I recenly won from ebay an 486DLC chip from Russia and the delivery charge (vire a US Intermediarary) was $2.99.

Anyway, AT based machines seem to use DS1287 (or equivalent) or DS1397. It seems that only EISA systems use the DS1387, but I could be wrong.

srg

P.S Thanks for looking

[bubach]

or u could have removed the battery from the motherboard...

[srg]

or u could have removed the battery from the motherboard...

The battery is built into these RTC chips. That's why I cut into mine, to get at the battery terminals.

Pull out the chip, and the RTC is still running from it's internal battery.

srg

[Eero Ränik]

Sorry, I didn't find the chip...

[Alec Voropay]

The Dallas DS1387 == DS1385+battary+xtall. . It seems, you broke the xtall (pins 2,3). Try to find a DS1387 or DS1385 PDF description and repair it. (It's easy. I did the same mistake a year ago trying to clear password on old SiS 486 EISA )

[Alec Voropay]

Documentation: http://www.mit.edu/afs/sipb.mit.edu/contrib/doc/specs/ic/clock/ds1385-87.pdf

The DS1385/DS1387 is a "RAMified Real Time Clock 4K x 8". This is equavilen for the DS1287 (generic IBM PC RTC, MC146818A clone) plus a 4K of RAM used for storing EISA configuration.