A VCR tape is pretty intricate device in its own right, and it's a classic miracle of mass production. It is amazing what you can buy for $2!
If you take a video tape apart, you will find that it contains:
- The top and bottom pieces of the outer shell
- A moving, spring-loaded door to protect the tape
- Two spools to hold the tape
- An 800-foot (244-m) long, 1/2-inch (1.3-cm) wide piece of oxide-coated Mylar tape that acts as the recording medium
- Several low-friction rollers to guide the tape across the front of the shell
- Two spring-loaded locks to prevent the tape from unrolling inside the cassette
- Several screws to hold the whole thing together
When the tape is inserted into a VCR, the VCR uses a lever to release and open the door, exposing the tape. It also inserts a pin into the hole to disengage the two locks on the spools. At that point, the drive can extract the tape and play it.