The software to required to drive network communications consists of a 4K machine code program, this normally resides in a system at address A000 (hex). For an Acorn system 2, 3 or 4 the software may be supplied in EPROM or on some other media. If supplied in EPROM the IC should be fitted in a memory card of issue 3 or later and enabled at A000 (hex). If supplied on other media the software must be loaded into a 4K RAM space at A000 (hex), this will often necessitate the fitting of an extra RAM card. Other memory requirements (for block zero byte allocations etc) are detailed in the network software users manual.