I’m not sure if Final Cut

I’m not sure if Final Cut Express 1.0 has this option, but this is how it’s done on Final Cut Pro:

File > Log and Capture

Click on "Capture Settings" tab

Click on "Scratch Disks…" button

Set "Limit Capture Now To": xx Minutes

If you don’t see that option in Final Cut Express 1.0, you probably can’t change it.

~kw