Abstract: A method of bidirectional data transmission between a computer system comprising at least two computers and at least one peripheral unit e.g. a magnetic tape terminal via data paths. The computers have different control unit address administration using addressing logs. Each of the peripheral units has a unique control unit address and is connectable via normal data path to that computer which has a consistent control unit address. The procedure provides detecting the addressing logs on the data paths, whereby an addressing compatibility device is switched into the data path of a computer having a control unit address which is not identical (inconsistent) to the control unit address of the peripheral unit. An addressing generator is set to the designated control unit addresses.