h6. [[Portable]] h6(. » [[Portable SWI Calls|SWI Calls]] h6((. » [[Portable_Speed2]] h6(((. » Portable_Speed2 4 h2. Portable_Speed2 4 h5. (SWI &42FCE) |_<^{width:4em}. Entry | | |<^. R0 |<^. 4 (Reason code) | |_<^{width:4em}. Exit | | |<^. R0 |<^. Number of available CPU speeds | h4. Use The purpose of this call is to return the number of different CPU speeds that are available. h4. Notes Due to hardware restrictions or for performance reasons, most systems will only support a limited number of CPU clock rates. This call, along with [[Portable_Speed2 5]] and [[Portable_Speed2 6]] allow the user to enumerate the list of available clock rates. Index 0 is always the slowest available speed, and R0-1 is always the highest available speed. To find the current CPU speed, see [[Portable_Speed2 0]]. To set the CPU speed, see [[Portable_Speed2 2]] or [[Portable_Speed2 8]] (to set the desired 'slow' and 'fast' speeds), and [[Portable_Speed]] (to switch between the configured 'slow' and 'fast' speeds). h4. See also * [[Portable_Speed]] * [[Portable_Speed2]] * [[Portable_Speed2 0]] * [[Portable_Speed2 2]] * [[Portable_Speed2 5]] * [[Portable_Speed2 8]] * [[Portable SWI Calls]]