OS_Pointer (changes)
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OS SWI Calls
» OS_Pointer
OS_Pointer
(SWI &64)
| Entry | |
|---|---|
| R0 | Reason code |
| All other registers are dependent on reason code | |
| Exit | |
|---|---|
| Registers dependent on reason code | |
Use
The purpose of this call is to perform a pointer(mouse) operation.
Notes
The action performed depends on the reason code value in R0.
Many versions of RISC OS contain a bug which will cause OS_Pointer to malfunction or crash if called with an unsupported reason code. Therefore, care must be taken when attempting to make use of reason codes 2 and above.
Internally this call makes use of the PointerV software vector to communicate with the pointer driver(s).
Reason Codes
| # | Hex # | Action |
|---|---|---|
| 0 | &00 | Get pointer type |
| 1 | &01 | Set pointer type |
| 2 | &02 | |
| Read pointer presence (NCOS only) |
See also
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