Abstract: The invention relates to a portable user controlled pointing peripheral device enabling connection of a memory and/or microcomputer module (44) to a processing machine, without requiring a specific connector and/or interface circuit, while preserving the portable nature of such a module. The main characteristic of the invention resides in the fact that the device additionally constitutes a pointing peripheral (47, 48, 49), such as a "mouse", and the electronic circuits of the device are arranged to use conductors (RXD, TXD, RTS, DTR) which are shared between the machine and the device in order to permit the use of the pointing functions and the use of the functions of the module.