Scope of Application:

This method is applicable to the cloning of iButtons including DS1977, DS1982, DS1985, DS1991, DS1994, DS1995, DS2502, DS2505 and other models. For DS1977 and DS1991 in particular, the password must be cracked first before analog cloning can be performed using this solution.

Basic Principles:

Each TM-type iButton has a unique 64-bit serial number (UID), namely the ROM code. Since the ROM is non-writable, if the data of an iButton is associated with its ROM, directly cloning the data of a functional iButton to another one will result in a non-usable cloned iButton.

To address this issue, we use a microcontroller unit (MCU) to simulate the ROM. When the device sends a ROM reading command, the MCU outputs the simulated ROM code; while when the device reads or writes iButton data, the actual iButton responds to the operation.