brk module

  external
    _end
    _cerror

  internal
    nd
	word    :=2
	_end
  
  global
    brk procedure
      entry
	ld	r0,r7
	xor	r4,r4
	sc	#17
	ld	r2,r4
	jp	c,cerror
	ld	nd,r0
	ret
    end brk

    sbrk procedure
      entry
	ld	r0,r7
	ld	r2,nd
	add	r0,r2
	ld	r1,r0
	dec	r1,#1
	dec	r2,#2
	cpb	rh1,rh2
	jr	z,t1
	sc	#17
	ld	r2,r4
	jp	c,cerror
t1:
	ld	r2,nd
	ld	nd,r0
	ret
  end sbrk
end brk