OS_Byte 121 (changes)
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Programmer's OS Reference SWI Manuals Calls
» Part OS_Byte 15 – SWI Calls
» OS_Byte 121OS
» OS_Byte
» OS_Byte 121
OS_Byte 121
(SWI &06)
| Entry | |
|---|---|
| R0 | 121 (&79) |
| R1 | Key to start at, or key EOR &80 for single key |
| Exit | |
|---|---|
| R0 | Preserved |
| R1 | For range check: key pressed, or &FF if none pressed |
| For single key: &FF if key pressed, or other if not | |
| R2 | Corrupted |
Use
The purpose of this call is to check which keys are being pressed.
Notes
This call can also be used to determine which mouse button has be clicked.
OS_Byte 122 is identical to this call, except that it ignore any key that has a value of less than 16. This includes; Shift, Ctrl, Alt and mouse keys.
See also
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