There is no virus known to F-Secure anti-virus products by this name. However, there is a well-known false positive on 'Readiosys' by Intels and Trends antivirus products on some boot sectors - usually these boot sectors have been slightly corrupted by Anticmos virus but are not actually infected.
If F-Secure anti-virus products don't complain about 'Radiosys-infected' boot sectors, ignore the warning and get an update to your Intel/Trend scanner. You can 'fix' the boot sectors and get rid of the false alarm by running F-Secure's FIXBOOT to the floppy.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.