collapseos/blk/300

PC ORG @ 0x1b + ! ( next )
( This routine is jumped to at the end of every word. In it,
  we jump to current IP, but we also take care of increasing
  it by 2 before jumping. )
	( Before we continue: are stacks within bounds? )
    0x1d BCALL, ( chkPS )
    ( check RS )
    IX PUSHqq, HL POPqq,
    DE RS_ADDR LDddnn,
    DE SUBHLss,
    JRC, L2 BWR ( IX < RS_ADDR? abortUnderflow-B298 )
    E 0 IY+ LDrIXY,
    D 1 IY+ LDrIXY,
    IY INCss,
    IY INCss,
    ( continue to execute )