h6. [[OS SWI Calls]] h6(. » [[OS_Byte]] h6((. » OS_Byte 216 h2. OS_Byte 216 h5. (SWI &06) |_<^{width:4em}. Entry | | |<^. R0|<^. 216 (&D8) | |<^. R1|<^. EOR value | |<^. R2|<^. AND value | |_<^{width:4em}. Exit|_<^. | |<^. R0|<^. Preserved | |<^. R1|<^. Previous length | |<^. R2|<^. Paged mode line count (see [[OS_Byte 217]]) | h4. Use The purpose of this call is to read or write the count of characters left in the currently active function key definition. h4. Notes If this count is non-zero then [[OS_ReadC]] is reading from a function key definition rather than the current input stream. Writing a 0 length will cancel the current function key expansion - the effect of writing any other value is indeterminate. h4. See also * [[OS_Byte]] * [[OS_Byte 217]] * [[OS_ReadC]]