RISC OS USB Support for the development and use of USB. http://www.riscos-usb.com/

USB Index Support page for the Castle USB card. http://www.castle.org.uk/support/usb/

Simtec Net100 100 Megabit Ethernet Network Interface Card (NIC. http://www.simtec.co.uk/products/AUNET100/

Simtec USB 11 Podule Interface suitable for Acorn computers, including the RISC PC, A7000 and A5000. http://www.simtec.co.uk/products/AUUSB11POD/

Castle 10/100Base-T Ethernet Card High speed network interface cards available in podule form or NIC. http://www.castle.org.uk/castle/graphics/Upgrades/Specifications/100BaseT.htm

Castle Network Cards From the current manufacturer of Acorn computers. http://www.castle.org.uk/castle/inter.htm

MIDI Max II ESP's MIDI expansion podule card. http://www.cybervillage.co.uk/acorn/esp/mmax.htm