Difference between revisions of "OSBYTE &B3"
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[[Category:OSBYTE]] | [[Category:OSBYTE]] | ||
| − | OSBYTE &B3 (179) - Read/Write primary OSHWM | + | OSBYTE &B3 (179) - Read/Write primary OSHWM/ROM polling semaphore |
| − | + | On the BBC, B+ and Electron, this contains the page number of OSHWM | |
| − | and | + | ignoring any font implosions and explosions. |
| + | |||
| + | On the Master onwards, the font is always exploded, and this location | ||
| + | contains the ROM polling semaphore. When the semaphore is non-zero the | ||
| + | 100Hz ROM service call &15 is sent to ROMs. The semaphore is normally | ||
| + | accessed with *FX23 to increment it and *FX24 to decrement it. | ||
==See Also== | ==See Also== | ||
| − | * | + | * [[OSBYTE &16|OSBYTE &16]] - Increment ROM polling semaphore |
| + | * [[OSBYTE &17|OSBYTE &17]] - Decrement ROM polling semaphore | ||
| + | * [[OSBYTE &B9|OSBYTE &B9]] - Electron ROM polling semaphore location | ||
| + | * [[Paged ROM service calls]] | ||
[[User:Jgharston|Jgharston]] 22:30, 26 May 2009 (UTC) | [[User:Jgharston|Jgharston]] 22:30, 26 May 2009 (UTC) | ||
Revision as of 01:40, 15 December 2013
OSBYTE &B3 (179) - Read/Write primary OSHWM/ROM polling semaphore
On the BBC, B+ and Electron, this contains the page number of OSHWM ignoring any font implosions and explosions. On the Master onwards, the font is always exploded, and this location contains the ROM polling semaphore. When the semaphore is non-zero the 100Hz ROM service call &15 is sent to ROMs. The semaphore is normally accessed with *FX23 to increment it and *FX24 to decrement it.
See Also
- OSBYTE &16 - Increment ROM polling semaphore
- OSBYTE &17 - Decrement ROM polling semaphore
- OSBYTE &B9 - Electron ROM polling semaphore location
- Paged ROM service calls
Jgharston 22:30, 26 May 2009 (UTC)
