OSBYTE &17
OSBYTE &17 (23) - Decrement Polling Semaphore
This call decrements a counter, which when zero will stop the (type &15) polling calls from being sent to ROMs at 100Hz. On exit: X=preserved - Polling semaphore exists X=&FF - Polling semaphore not implemented
See Also
- OSBYTE &16 - Increment Polling Semaphore
- http://mdfs.net/Docs/Comp/BBC/Osbyte00
Jgharston 21:32, 26 May 2009 (UTC) Jgharston (talk) 02:04, 6 November 2020 (CET)