The Simtec USB interface is a 16 bit podule with 2 host ports and a device port. The USB interface works with most Acorn RISC OS computers from the A300/400 via the A5000 to the RiscPC. and is compatible with RISC OS 3.1 and higher The main features of the USB interface are:

• Dual function podule with 16bit EASI space compatibility
• Philips ISP1161A USB 1.1 compliant host controller with 2 port root hub
• 128KB of user re-programmable flash ROM. Reprogramming utility (!Snafu) supplied.
• Two root hub host ports, with power switching ensuring compatibility with the podule specification
• Full over-currrent and ESD discharge protection for reliable operation during plugging and unplugging of devices
• High/low speed multi-function device port with concurrent host and device operation (not supported in software)
• Mature and proven hardware design.

The Universal Expansion card Fitting instructions are available HERE .
 
The documentation and software for the USB Interface are still available from the Simtec web site under legacy products