I wonder if Asimov or Clarke had a Roomba?

As I type this unillustrated post, my new robotic vacuum cleaner is running round the house, entertaining both me and the cats while sucking up bits of this and that. Charming until it gets something biggish stuck in it's maw, the Roomba tackling a crafter's space needs an owner handy with a screw driver to perform the robotic equivalent of a Heimlich maneuver. A Roomba's been on my wish list since they were first available. Recently I spotted one at my favorite thrift store for $5. I snapped that puppy up. It had no obvious evidence of damage and was with its charger and a wall hanger. No invisible walls or remote control, but they're replaceable if I find I must have them, but I have no indoor steps and don't really want another remote control to keep track of. Now there was a downside to this bargain. The rechargeable battery was no longer holding a charge. Not unexpected at all. After researching Roomba discussions, retailers, etc. I downloaded its manual and bought a replacement battery pack from an eBay seller for $40 (including shipping). It came with the special triangle-tip screwdriver needed to open Roomba's battery case, and it was a fast and easy process inserting the new batteries. They charged up fully over night. Yay! $45 Roomba with a brand new battery! Am I tickled or what? If you're curious about them, YouTube has videos of them with/without animal interactions and with/without hackers' adaptations. PS: It ran from 12:35 to 2:23, only pausing for me to empty the dust bin and untangle a couple of cat toys. 108 minutes!