OSBYTE &6F

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OSBYTE &6F (111) - Read/Write Shadow RAM Switch

   X b7=0 no stack operation
     b7=1 pop state from stack (reading), push state on stack (writing)
     b6=0 write switch state
     b6=1 read switch state
     b0=0 select video RAM
     b0=1 select shadow RAM
   On exit, X contains the previous switch state:
     b0=0 video RAM
     b0=1 shadow RAM

See Also

http://mdfs.net/Docs/Comp/BBC/Osbyte00

Jgharston 21:17, 26 May 2009 (UTC)

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OSBYTE