h6. [[Portable]] h6(. » [[Portable SWI Calls|SWI Calls]] h6((. » Portable_Speed h2. Portable_Speed h5. (SWI &42FC0) |_<^{width:4em}. Entry | | |<^. R0 |<^. EOR mask| |<^. R1 |<^. AND mask| |_<^{width:4em}. Exit | | |<^. R0 |<^. Old speed value | |<^. R1 |<^. New speed value | h4. Use The purpose of this call is to set the processor speed. h4. Notes The new speed is set as: <code>New value = (old speed AND R1) EOR R0</code><br /> Currently supported speed settings are: |<^. 0|<^. Fast| |<^. 1|<^. Slow| Some hardware allows programs to exert more control over the CPU speed by SWI [[Portable_Speed2]] to specify what clock rates the 'slow' and 'fast' speed settings equate to. h4. See also * [[Portable_Speed2]]