OSBYTE &A3

OSBYTE &A3 (163) - X=242 (Acornsoft GXR 1.20)

   Y=0     resets the dot-dash pattern & length to defaults
   Y=1..64 set dot dash pattern repeat length
   Y=65    return status returns X=b0..5 current dot dash pattern repeat 
                                         length (0 means 64 though)
                                   b6    if set flood fill is always active
                                   b7    if set GXR ROM is turned on
                                 Y=number of pages allocated to sprites
   Y=66    return info on current sprite returns X=pixel width 
                                                 Y=pixel height
           if X=Y=0 then the ROM is not fitted, or no sprite is selected

   X=242    (RISC OS 1.00)
   Y=0     resets the dot-dash pattern & length to defaults
   Y=1..64 set dot dash pattern repeat length
   Y=65    return status returns X=b0..5 current dot dash pattern repeat 
                                         length (0 means 64 though)
                                   b6    if set flood fill is always active
                                   b7    if set sprites are always active
   Y=66    return info on current sprite returns X=pixel width 
                                                 Y=pixel height 

   X=243    (65Tube emulator)
   Y=4     find code address, on exit if Y<>0, XY=address to jump to.
           Called on Tube reset, *BASIC and NMIs to ask for any code
           entry address
   Y=6     find *command to execute, on exit if Y<>0, XY=>*command to
           execute. Called on Tube reset to ask for any startup command.

   X=255    (VIEW)
   Y=1     read VIEW's ROM workspace byte at &DF0+romnum.
   Y=&81   set VIEW's ROM workspace byte at &DF0+romnum to &80.

See Also

• http://mdfs.net/Docs/Comp/BBC/Osbyte80

Jgharston 22:16, 26 May 2009 (UTC)