IBM/XT Y2K Compliancy

From: Allison J Parent <allisonp_at_world.std.com>
Date: Sat Aug 7 22:39:52 1999

<> I have five 486 boards that hae older RTC that roll over from 1999 to 198
<> they do however set manually to 2000!
<
<Is this the clock chip (I would be _very_ supprised if it were the
<case), or how the BIOS/OS reads the chip.

In these cases (early 486s) the bios is reading a chip with a known bug.

<Now, some PC BIOSes/OSes will take an invalid (too early) year as being
<1980. So the clock rolls over from 1999 to 1900, and the _software_
<changes that to 1980 (as otherwise it's too early a date). That's why you
<can manually set them to 2000.

A few chips were designed that way, as their date of origin was later than
1980.

<The chip itself is working correctly (as designed). The software is
<misusing it ;-).

The one on my s100 board is definatly broke... I wrote the bios!

Allison
Received on Sat Aug 07 1999 - 22:39:52 BST