This is a brain analysis device, computer storage unit and data transfer unit capable of making an of-site backup of your entire personality.
In a materialistic universe, a personality is no more than a collection of data. This includes all Skills and Schticks. This data can be backuped in a safe location, and if the original is indisposed, a copy can be made. Depending upon technological spophistication, this copy may have to be a Cyborg or may be made partially of force-grown clone tissue.
In a spititual sense, this is of course impossible. There is only one soul, and no copy can duplicate your individual essence. Any newly-decanted copy has all Chi at zero. But the spiritual essence of the character will slowly grow back, at the rate of one Chi point per session or game month (as appropriate).
A Brain Tape is not so much a system as a phenomena, though a Cyber system is at the core of it. If you have nobody to administer the recreation of your body for you, you won't live again. If someone can destroy or corrupt your backup, you are also out of luck. Worse, someone may well get hold of the data, make a copy, and brainwash it into serving them. What happens to the spirit of a copy is anybody's guess, but clone rivalry is very common. One can also upload your personality into a BehaviorChip or into an AI construct, gaining access to your Skills and knowledge without giving the copy a body to cause mischeif with. But all these additional complications are more plot hooks than actualparts of the schtick.