Difference between revisions of "OSBYTE &71"

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The setting is stored in the [[OSBYTE &FB]] variable.
 
The setting is stored in the [[OSBYTE &FB]] variable.
  
==See Also==
+
==See also==
 
* [[OSBYTE &49]] - Check for Integra-B shadow memory
 
* [[OSBYTE &49]] - Check for Integra-B shadow memory
 
* [[OSBYTE &6C]] - Select Master/Integra-B shadow memory
 
* [[OSBYTE &6C]] - Select Master/Integra-B shadow memory

Latest revision as of 19:28, 22 January 2021

OSBYTE &71 (113) - Select Main/Shadow for Display
   On entry:
       X=0 Use whatever memory the current screen MODE uses
       X=1 Use main memory
       X=2 Use shadow memory
   On exit:
       X=preserved
   RISC OS:
   The value of X can be greater than 2 as well, and instructs the video
   hardware to use the bank at screenbase+(X*modesize)

This call specifies which bank of memory the Master video display hardware accesses. Using this and OSBYTE &70 a program can use the VDU to write to one bank of memory while the other is being displayed.

The setting is stored in the OSBYTE &FB variable.

See also


Jgharston (talk) 01:12, 4 April 2015 (UTC)