OS_Byte 254 (changes)
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Programmer's OS Reference SWI Manuals Calls
» Part OS_Byte 15 – SWI Calls
» OS_Byte 254OS
» OS_Byte
» OS_Byte 254
OS_Byte 254
(SWI &06)
| Entry | |
|---|---|
| R0 | 254 (&FE) |
| R1 | EOR value |
| R2 | AND value |
| Exit | |
|---|---|
| R0 | Preserved |
| R1 | Value before being overwritten |
| R2 | Corrupted |
Use
The purpose of this call is to enable or disable the effect of Shift and Ctrl on the numeric keypad or to read the current state.
Notes
These keys may modify the code just before it is inserted into the input buffer.
If R1 is zero, then Shift and Ctrl are enabled. Any non-zero value will disable them. This is the default.
If Shift/Ctrl are enabled, then the following action occurs depending on the value generated by a keypad key:
| * key value >= &80 | Shift exclusive ORs the value with &10 Ctrl exclusive ORs the value with &20 |
| * key value <&80 | Shift and Ctrl still have no effect |
If NumLock is off, then a *Fx 254 0 makes the keypad act exactly like the cursor keys, including Shift, Ctrl or both.
The base value used for numeric keypad interpretation can be read and written with OS_Byte 238.
See also
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