A new driver is available for the AT&T PC6300 to fix the clock problem.
The driver is available for downloading on AIX and is located as
/usr/local/pub/pc/att/clk63.sys

The file should be pointed to with a line in your config.sys file which
should look like:

	device=drive:\path\clk63.sys

"drive" would be replaced by the drive letter where the file is stored
and "path" would be replaced by the complete path to the files location
on that disk drive.

When downloading the file, please use binary file type.

This fix should allow the clock to use correct dates until 1997.