OSBYTE &AD
OSBYTE &AD (173) - Read address of keyboard translation table
On entry: newvalue = (oldvalue AND Y) EOR X
On exit: X=high byte of address of keyboard translation table or keyboard number. See OSBYTE &AC.
The top bits indicate if the MOS keyboard driver is being used or an alternative keyboard driver is being used.
- If Y=%11xxxxxx, MOS keyboard driver
- If Y=%10xxxxxx, sideways ROM keyboard driver
- If Y=%0xxxxxxx, International keyboard driver.
If Y<>%11xxxxxx (ie Y < &C0), the byte holds the keyboard number and implementation-specific flags:
- b0-b5 : keyboard number &00-&3F, &00=none or default
- b6 : International keyboard driver: NUL needed flag
- b6-b7 : MOS or external keyboard driver
See Also
- OSBYTE &46 - Set country (both keyboard and alphabet)
- OSBYTE &47 - Set keyboard and alphabet
- OSBYTE &AC - Read/write keyboard handler setting
- OSBYTE &F0 - Read/write country code
- http://mdfs.net/Docs/Comp/BBC/Osbyte00
- http://mdfs.net/Docs/Comp/BBC/OsbyteA6
- http://mdfs.net/System/ROMs/AcornMOS/Compact511
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Jgharston 22:24, 26 May 2009 (UTC) Jgharston (talk) 21:52, 13 September 2019 (CEST) Jgharston (talk) 03:26, 15 October 2020 (CEST) Jgharston (talk) 23:23, 18 October 2020 (CEST)