Abstract: A distributed computer architecture eliminates the need for numerous transmission lines that extend beyond the housing of the computer and its communications server, thereby reducing crosstalk and space consumption. The distributed computer architecture includes a plurality of computer systems each connected through communications servers to a plurality of communications networks of various types. Each computer system includes a plurality of terminal adapters that are connected to at least one network of the CSMA/CD type, each terminal adapter being connected to at least one terminal via a respective transmission link, and each terminal adapter managing and transferring frames from the network to an associated terminal, and vice versa, and adapting the protocols and transmission speeds used in the network and on each transmission link.

Abstract: A host structure is provided for terminal adapters that are part of a distributed computer architecture. Each computer system is in turn connected to a number of synchronous or asynchronous terminals via the network and terminal adapters, each terminal adapter connected, on one hand, to the network and, on the other hand, to at least one terminal via a synchronous or asynchronous transmission link. The host structure can contain a number of adapter cards, each containing the electronic circuit of an adapter, and is composed of a first compartment with the adapter cards, and a second compartment with an equal number of connection cards. The connection cards each enable connecting a number of terminals to a particular adapter.

Abstract: An access unit to a transmission medium formed of two telephone pairs of a local area network with carrier sense multiple access with collision detection, connected to a station containing a send current generator, a receive signal generator and a collision detector receiving the signals sent by the station and every signal sent by other stations. The unit includes a collision simulation circuit receiving a first send voltage U.sub.E and the receive singal V.sub.R, which sends to the collision detector either a second send voltage V.sub.E if the connected station is the only one sending, or the receive signal if the latter is not sending, or a collision simulation signal of which the average value is such that the collision detector signals a collision to the connected station.