OSBYTE &83

OSBYTE &83 (131) - Read OSHWM, bottom of user memory

   On exit X and Y hold the lowest address of user memory, used to
   initialise BASIC's 'PAGE'. If b7 of A is clear, then A:Y:X holds
   the 23-bit address of the bottom of user memory, as when running
   6502Turbo code on a CoProcessor, which returns A=&01, XY=&0000.

See Also

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

Jgharston 21:58, 26 May 2009 (UTC)