services With the introduction of Acorn's Unix workstations running RISC iX, an envisaged application for Econet was the use of Master 128 computers acting as terminals to these Unix systems. Such systems also offered the capability to act as bridges between Econet and Ethernet networks, offering routing facilities to any Unix machines attached to the Econet, this being enabled by the IP-over-Econet support in RISC iX. X.25 network services An Econet X.25 gateway product was offered by Acorn, providing access to X.25 networks for computers on an Econet, with the X25 Terminal ROM and the existing Acorn DNFS ROM needing to be fitted to computers to enable access to X.25 services, with the Terminal ROM providing terminal emulation and file transfer functionality. The gateway hardware consisted of the core functionality of a BBC Micro, this being the network service module connected to the Econet, combined with a Z80 second processor connected via the Tube interface, this acting as the gateway module and having 16 KB ROM and 32 KB of private RAM, augmented by another board with a Z80 processor with 32 KB of private RAM, this being the X25 module accessing the X.25 line. The gateway and X25 modules communicated via 16 KB of dual-ported shared RAM. The X25 module was designed by Symicron and ran the "proven" Symicron Telematics Software (STS). Econet users would send network service requests to the gateway that would be forwarded by the STS functionality of the gateway to the X.25 network. Incoming X.25 calls would be forwarded by the STS functionality to the network service functionality and on to the Econet. Network service requests could employ X.25, Yellow Book Transport Service, and X.29 protocols. Comparison with modern systems While Econet was essentially specific to the Acorn range of computers, it does share common concepts with modern network file systems and protocols: Remote Procedure Call – Almost all network operations were performed via a primitive remote procedure call system, either by passing a command line direct to the file server, or by passing an operating system call parameter block. The logon command *I AM was processed by passing the whole command line and reading back the result code. Access Permissions – By the time of the Acorn Level 4 File Server and the SJ Research MDFS systems, Econet file servers had a full user name and password system with public and private attributes. These