You can assume the highest capacity PATA hard disk built for laptops (2.5" form factor?). But it really depends on your motherboard, specifically the BIOS. I'm not sure where you can get that information though.
http://catzdesigns-server-1.webs.com/myinspiron.jpgYo, Inspiron 1200 OWNZ Heres my specs just so you can see the potential in it. 1st i got 1gb of ram from ebay too add 256mb - 1gb. Then i got the compaq nc6000 CPU (pentium m 1.7) 1.3-1.7 GHZ huge change. Then i got a Western Digital Scorpio Blue PATA 250GB 5400rm HDD (30gb-250)(4200-5400rpm NOTABLE DIFFERENCE) I then installed windows vista Home Premium but then i upgraded to windows 7 home premium (which runs extremely fast on here) now i can run games Like GTA San Andreas on high resolution i have a 20 in VGA monitor configured as a dual screen. YOU HAVE TO GET A REPLACEMENT BATTERY LOL THE OEM ONE SUCKS. I also am able to run resident evil 4. Only thing im too scared to change is the graphics card therefore you have 122mb video memory which isnt horrible but will not run aero on windows vista and 7 (not a huge deal). I get 15 seconds boot time 8 seconds login time. Very fast computer now running the latest and most up to date OS very smoothly. I also painted and stickered it :D. ans yes this is an actual inspiron 1200
originally all black with circle dell logo on back. First Picture is a stock photo. The Second picture is of mine the way i have it set up. Dont hesitate to email me if you need help with this laptop. I know everything about these.