OSBYTE &91

OSBYTE &91 (145) - Read character from buffer

   X=buffer number
   On exit Y=character got, or C=1 if the buffer was empty
   (RISC OS 1.00)
   If the chosen buffer is X=9 (mouse) then interrupts should be disabled 
   while inserting bytes into the buffer incase the real mouse starts to put
   bytes in between yours.
   Top bit set characters should be entered into the keyboard buffer preceded
   by a byte 0 to prevent them from being mistaken for F-key presses or ALT
   and CTRL key shortcuts.

See Also

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

Jgharston 22:03, 26 May 2009 (UTC)