interrupts off
  garbage <- free-pointer - limit
  tem2 <- free-pointer
  jump-greater-than
  md <- a0
  vma-start-write-early <- tem2
  free-pointer <- tem2 + 2
  md <- a1
  vma-start-write-cdr-early <- tem2
  interrupts on
  return tem2 + dtp-list


AREF
  open o1 <- index check dt fix,  24 bit
  ldb dt array-pointer
  call less than negative index
  dispatch-call o0 <- array-pointer

art-q:
  vma-start-read-early array-pointer
  tem1 <- dpb easy-bit index, 24 bit
  md - tem1, 24 bit
  tem2 <- array-pointer + index + 1
  jump greater index out of bounds
  vma-start-read-early <- tem2
  x
  return md


ASET
  open o2 <- data
  o1 <- index check dt fix,  24 bit
  ldb dt array-pointer
  call less than negative index
  dispatch-call o0 <- array-pointer

art-q:
  vma-start-read-early array-pointer
  tem1 <- dpb easy-bit index, 24 bit
  md - tem1, 24 bit
  tem2 <- array-pointer + index + 1
  jump greater index out of bounds
  md <- data
  vma-start-write-early <- tem2
  return data




(move vma-start-read aptr dt-trap-if-not-array-ptr)
(open-call aref <dest> (o0 index))

aref
(ldb nop *zero* a0 (byte 2. 22.) dt-trap-if-not-fixnums)
(alu l+r nop-no-overflow a0 md bw-24 br-not-zero)
(branch index-bad (alu load-status-r nop *data-type-byte-spec*) bw-16 br-greater)
(branch hard (alu dpb a1 *dtp-locative* vma) pw-rr)
(alu l+r+c vma-start-read a1 a0 carry-in-1 bw-24)
(nop)
(return md)