Programmer's Reference Manual. Network services At the time and in the markets for which Econet was developed, the main purpose of computer networking was to provide local area shared access to expensive hardware such as disc storage and printers. Acorn provided software for the BBC Micro to implement a file server, and optionally a printer server also. The original file server was very basic, essentially allowing limited access to a floppy disc over the network. The server software was further developed over many years, and Acorn and other manufacturers also produced dedicated Econet servers based on various technologies. So the servers available fell into roughly three categories: The Acorn Fileserver, from Level 1 through Level 4, running on a standard computer (BBC, Master or Archimedes) and providing simple file and print services. The dedicated Acorn Filestore units, running on dedicated hardware with higher capacity and more facilities. Third party units (notably from SJ Research), again running on dedicated hardware and with their own implementations of the server software. These were compatible with the Acorn implementations, but with additional enhancements. (Notably, Oak Solutions collaborated with Acorn to develop the Level 4 Fileserver solution.) The machine type numbers listed in the "Supported systems" section above are an indication of the range of hardware that was available or planned. Additional services could be implemented, using the network API provided. Short utilities such as network chat programs were often published in magazines or distributed by sharing among users; these made use of the Econet protocols to work alongside the basic file and print services. Larger software packages (some of them commercial) were available that provided services such as Teletext and modem drivers. Filestore Acorn emphasised the Filestore in the late 1980s as a solution for small workgroups, offering a base unit with optional hard disk storage modules. The device was similar in concept to what is now termed Network Attached Storage, being a standalone unit dedicated to serving files over a network. The Filestore was a 65C102-based machine with 64 KB of RAM, 64 KB of ROM, Econet connectivity, two 3.5" floppy drives, a parallel printer interface, expansion bus, Econet clock and termination circuits, a real-time clock, and a quantity of battery-backed RAM. The battery-backed RAM was used to hold configuration and authentication details. Initially, hard disk expansion was offered in the form of the E20 module providing a 3.5" 20 MB Winchester disk