Yes you can...
Groovejivey, yes, you CAN just jam a 250MB Iomega Zip drive into the BR-8 and have it work. It's very easy, in fact. I can do it in 10 minutes, start to finish.
Requirements: a 250 MB internal ATAPI (IDE, same thing) Zip drive. A jumper. A couple Phillips head screwdrivers. A towel.
Unplug everything, and lay out the towel on your work surface. Put the machine upside down on the towel. Take the bigger screws out from the perimeter of the bottom plate, then the smaller screws, then the four inside screws (they hold the Zip drive to the bottom plate).
Remove bottom plate and put safely aside.
Unplug the Zip drive's power cable--that's the small four-plug thingy in the corner.
Look at the two retaining screws on the sides of the Zip drive, and notice the retaining posts right next to these two screws. Remember what's what. Unscrew the retaining screws, which hold the drive brackets.
Take the drive up and work the IDE ribbon cable out of its place on the back of the drive. This is the hardest thing you'll have to do; it takes a bit of working, and you must work carefully and apply just enough force to remove it without doing any damage. Great.
Okay, you've got the drive in your mitts, and it's out of the BR-8. Now, remove the brackets on its sides. Make sure you're keeping track of where exactly the brackets go on the drive, and what side is up (the label side will face into the machine as you place it in), because you're going to have to put them back there on the 250 drive. Take the protective foil off with the racks. (I kept them in one place, relatively located, so I could drop the 250 right in and attack the foil and brackets correctly.)
Get your 250 MB drive, and make sure that the jumper is set for the Master setting. (It's shown on the label on the drive.) If you don't have a jumper, hey--take the one from the 100 drive.
Now put the protective foil on (it covers the label side of the drive), and secure it by screwing on the brackets in the places they held on the 100 drive.
Ready to put it in! Now, place the drive back into the machine (slot out, right? foil facing into the machine, right?), placing the bracket retaining holes onto the posts. Screw it back in---note, don't screw it into the bracket posts, but the screw holes that you mentally noted, right?
Attach the cables--IDE ribbon cable and power cable. They can only go on one way, so if one won't push on you need to turn it over. Secure it all.
Put the bottom of the machine back on. Attach the four Zip drive screws first, securing the drive.
Now, screw in the wider screws around the perimiter, then the smaller. You're done.
Flip it over. Plug it in. Turn it on. Stick a 250 MB disk into it. Wonder at the over 2 hours of recording time in Standard mode, compared to the mere 49 minutes of a 100 MB disk, and over 3 hours in LV2 mode! Zowie!
Note that, of course, you have to use 250 MB disks to get more time. The drive will allow you to use your old 100 MB disks, yes, but you only get more time with more disk capacity. It's a 250 MB drive, it's not a miracle worker.
DS