The NICContinuing in the Acorn tradition, the RiscPC has a socket for a dedicated "NIC" (Network Interface Card). However as Econet was becoming rather old hat in the mid '90s with the inception of the RiscPC, the NIC was expanded to permit the inclusion of Ethernet cards. Indeed the main purpose of the NIC is for a 10-base-T/10-base-2 interface, though I believe 100-base-T cards are also available.
For compatibility purposes, Acorn supplied a small number of Econet cards which fit into this slot and connect by way of a somewhat unusual 15-pin D socket, rather like a "game" port on a typical PC's combi card.
In the picture below you can see an i-cubed ethernet card installed in my RiscPC. I would imagine that the Econet card will look not unlike the later series cards; I have not actually seen one.
Gateway servicesIt is possible to "gateway" most Acorn-era RISC OS machines by fitting an Econet card (either normal style or the RiscPC NIC, as appropriate), and then using an Ethernet podule for the TCP/IP side of things, such as the i-cubed EtherLan500 shown on the right.
This is aided by the "AUN" (Acorn Universal Networking) technologies which provide Econet transport layers on TCP/IP plus shared peer-to-peer access to drives, directories, etc. The upshot of this is Econet compatible, much zippier!