OSWORD &21 (33 ) - Execute code in I/O processor TubeLink
On entry: XY!0=I/O address XY?4=A register XY?5=X register XY?6=Y register XY?7=P register (only bit 0 significant - Carry flag) XY?8=semaphore byte On exit: If the code has been executed, the semaphore byte is incremented by one. Extended I/O addresses are used. &FFrrxxxx specifies ROM &rr, &FFFExxxx specifies shadow screen memory. Returned register values are returned in control block.
Jgharston 13:31, 26 May 2009 (UTC)