RISC OS Service Call Block Summary
                   ==================================

Number  Name                  Reference
&0xxxx  OS

&1xxyy  Filing System &xx

&105xx  NetFS
&108xx  ADFS

&40000
&40040
&40080
&400C0  Wimp
&40100

&40200  NetPrint

&45540  Draw

&80ACx  Service_Z80*          mdfs.net/Docs/Comp/Spectrum/RISCOS/EmulatedIO
&80ADx  Service_6502*         mdfs.net/Docs/Comp/BBC/RISCOS/EmulatedIO