KeyV 0
KeyV
» KeyV 0
Keyboard present
| Entry | |
|---|---|
| R0 | 0 (reason code) |
| R1 | Keyboard number |
| R2 | &4E6F4B64 (‘NoKd’)1 |
1 Available from RISC OS 5.06 onwards, or versions of RISC OS Select/Adjust with Kernel 10.23 or newer
Use
After a successful initialisation by the keyboard device driver, the driver should issue this call in order to notify the kernel that a keyboard is present.
Notes
If R2 contains the magic word ‘NoKd’, the kernel will disable its de-bouncing allowing, for example, a barcode reader to input characters faster than 10-15 cps. De-bouncing can be re-enabled by issuing this call with R2 set to 0.
Once this call has been issued, the driver should go dormant until it receives a KeyV 4 call, which indicates that the system is ready to start receiving key up/down events.
When the last keyboard that a driver manages is removed from the system, KeyV 16 should be issued in order to allow any other drivers to reconfigure the system to meet their requirements.
See also
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