OSBYTE &EF

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OSBYTE &EF (239) - Read/Write shadow screen state

This location is used by various shadow screen memory systems to hold the shadow MODE selection state.

 BBC B:
   Working value for OSBYTE 111.
 BBC B+/Master:
   *SHADOW/OSBYTE 114 value
         0: shadow screen will be selected on next MODE change
       <>0: non-shadow screen will be selected on next MODE change
 Electron:
   b0=Electron Master RAM Turbo mode (2MHz selected)
   b7=Electron Master RAM 64K mode (shadow screen enabled)

See Also

Jgharston 23:12, 26 May 2009 (UTC) Jgharston (talk) 22:50, 14 February 2016 (UTC)