HP Vectra XU5 Reference Manual page 50

Year of the ROM BIOS Release
0F000:00FEh = Year of ROM BIOS release in Binary Coded Decimal (BCD).
Length = one byte
Encoded as follows:
yy
Where yy is the difference between the current year and 1960 in BCD.
For example, if the current year is 1990, you would enter 1990 minus 1960 which is 30h
(when expressed in BCD).
Vectra XU Technical Reference Summary of the HP BIOS 50