h6. [[OS SWI Calls]] h6(. » OS_ReadVduVariables h2. OS_ReadVduVariables h5. (SWI &31) |_<^{width:4em}. Entry | | |<^. R0 |<^. Pointer to input block| |<^. R1 |<^. Pointer to output block (can be the same as R0) | |_<^{width:4em}. Exit | | |<^. R0 |<^. Preserved | |<^. R1 |<^. Preserved | h4. Use The purpose of this call is to read a series of VDU variables. h4. Notes The input block is a list of [[VDU Variables|VDU variable numbers]] (words) terminated by -1. Each variable is read, and its value is written as a word into the output block. Note: You can also read the [[Mode Variable Numbers|mode variables]] with this call. h4. See also * [[Mode Variable Numbers]] * [[VDU Variables]]