Difference between revisions of "OSBYTE &B3"

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[[Category:OSBYTE]]
 
[[Category:OSBYTE]]
OSBYTE &B3 (179) - Read/Write primary OSHWM
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OSBYTE &B3 (179) - Read/Write primary OSHWM/ROM polling semaphore
  
     This value contains the page number of OSHWM ignoring any font implosions
+
     On the BBC, B+ and Electron, this contains the page number of OSHWM
     and explosions
+
    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==
* http://mdfs.net/Docs/Comp/BBC/OsbyteA6
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* [[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
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* [[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 02:40, 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

Jgharston 22:30, 26 May 2009 (UTC)