Entry | |
---|---|
R1 | 81 (&51) |
R2 | Mode number, shadow bit clear |
R3 | Monitor type |
Exit | |
---|---|
R1-R3 | Preserved to pass on, else: |
R1 | 0 to claim service |
R2 | Substitute mode (mode number or mode Mode Selector Block) |
R3 | Preserved |
This service is issued by OS_CheckModeValid or a mode change when the monitor type is unknown by RISC OS, and the mode is not available with the current monitor type.
The monitor type can be ascertained by Service_ModeExtension.
This call is only issued for mode numbers, not Mode Selector Blocks.