Hi Leohuangdi
Thanks very much for your reply, and sorry for the delayed reply.
Re the HDD you are right, it cuts it up in 8gb segments, but actually uses the full 80gb.
Re the battery, and this is why it took me time to reply, the battery is actually on the underside of the motherboard (weird eh). It is an SII (Seiko) MS Lithium rechargeable battery, similar to the one shown in the attached link. Unfortuneately the small plate soldered to the battery covers the battery number. I can only see the MS and the F (no E), but not the numbers in between, so it looks like MS***F. Do you have any clue? Anyway I've never seen this type on sale. Looks like I have to just reset the date and time, everytime there is a power failure. I use a UPS, but that only lasts about 30 minutes.
Thanks alot for your help, though, Eddie
http://www.sii.co.jp/components/battery/productSpecBatEN.jsp?recordID=72