OSBYTE &49

OSBYTE &49 (73): Integra-B calls

  On entry:
    X=&FF - returns X=&49 indicating Integra-B is present
  On exit:
    X=&49 - Integra-B is present
    X=&FF - call unsupported
  
  On entry:
     X=&FE - initialise alarm
  On exit:
     ???
  
  On entry:
     X=%0000mmtt - update RTCUpdateOptions
           Options are set to (oldOptions AND mm) EOR tt
           b0=Alarm generates a User Event
           b1=Alarm generates Service Call &49
     If the options are set to non-zero, the RTC interupt enable is updated

See Also

• OSWORD &49 - Integra-B shadow memory calls
• OSBYTE &49 - Check for Integra-B shadow memory
• OSBYTE &6C - Select Master/Integra-B shadow memory
• OSBYTE &6F - Select Aries/Watford shadow memory
• OSBYTE &70 - Select memory for Master VDU access
• OSBYTE &71 - Select memory for Master video display
• OSBYTE &72 - Select future use of shadow memory
• OSBYTE &73 - Select shadow bank
• OSBYTE &74 - Check for Solidisk shadow memory
• Paging in video memory
• http://mdfs.net/Docs/Comp/BBC/Osbyte00

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Jgharston (talk) 20:29, 3 April 2015 (UTC)