OS_CheckModeValid (changes)
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Programmer's OS Reference SWI Manuals Calls
» OS_CheckModeValidPart 15 – SWI Calls
» OS
» OS_CheckModeValid
OS_CheckModeValid
(SWI &3F)
| Entry | |
|---|---|
| R0 | Screen mode to check (either mode number or Mode Specifier Block) |
| Exit | |
|---|---|
| If C flag unset, then Screen mode is valid | |
| R0 | Preserved |
| If C flag set, then Screen mode is invalid | |
| R0 | -1 = Screen mode is non-existent |
| -2 = Not enough memory | |
| R1 | Alternative screen mode to use |
| -2 = Unable to select alternative screen mode | |
Use
The purpose of this call is to check if it is possible to change to a specified screen mode.
Notes
This finds out whether you may change to a given mode or whether it is invalid, for example if the mode isn’t supported by the current monitor type or if there is no suitable MDF entry for a Mode Specifier Block.
If the mode is invalid then the returned value in R0 will indicate the reason why, and R1 may contain a suggested alternative mode.
See also
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