10/21/1999-vp4-686a- 2a5lhx49c-00
Post the BIOS message, too. It's a bit further up, on the same screen you located your BIOS ID string.
And, post any markings on your motherboard, or any clue that might be printed in your manual.
And, post any markings on your motherboard, or any clue that might be printed in your manual.