it was probably set up in a RAID 0 Array, both drives are setup to function together as one, half data is written to one drive, other half to the other, both can be read simultaneously and written to as well, theoretically doubling the performance of one drive, also doubling your storage you would normally have with just one drive.
down side, is no redundancy, no back up, if data gets corrupted, especially the OS, your whole array is screwed, and needs to be built back up from scratch.
other forms of RAID like RAID 1, can alleviate that, but then you lose the speed and storage factor, since its 2 drives one mirroring the other.
a 0+1 array would give you best of both, but would require 4 drives.
RAID 5 would only need 3, and be similar to 0+1.
so it sounds like the drives were setup in RAID 0
how to set it up like that, you'll have to consult someone with a similar laptop, laptop documentation that came with it, or on Toshiba's website, or contact Toshiba and find out, since the process can vary from product to product.
though enabling RAID should be accessible from the Laptops Bios, getting in to the bios though, is why I mentioned above to get the info.
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