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Notes and answers for Lab 09 (MARIE / Assembly Language)
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- Ian! D. Allen - idallen@idallen.ca - www.idallen.com

Not all questions will be marked - check all your answers against this
answer sheet:

References:
    ECOA2e Section 4.1-4.6, 4.8.1-4.9.1, 4.9.3, 4.10, 4.11.1, 5.4.2 and
    associated Chapter Slides
    Class Notes (via course home page): text_errata.txt

Not all questions will be marked - check all your answers against the
answer sheet when it is posted.

            AC   IR MAR  MBR  PC
load x    0020 1004 004 0020 001
add y     0011 3005 005 FFF1 002
store z   0011 2006 006 0011 003
halt      0011 7000 003 XXXX 004     XXXX = 0011 or 7000

2.Hand-assemble (without using MARIE) and answer on separate paper
  Question 13 on page 239.

    1108 3109 9106 3109 2108 7000 3108 9103 0023 0001

3.Answer on separate paper Question 14 on page 239.

   A     108
   One   109
   S1    106
   S2    103

4.Question 15a p.239:  i) Store 007  ii) Jump 00B   iii) Add 009

5.Read Address Modes, Section 5.4.2, and refer to Figure 5.3, Table 5.1,
  and Question 13 p.277.

  Given the instruction LOAD 2000, determine the actual value loaded into
  the accumulator and fill in the Addressing Move table below if the index
  register R1 contains the value 2100:

    Immediate  2000
    Direct     2200
    Indirect   2600
    Indexed (with R1)  3600

Note that most MARIE instructions are Direct Addressing. MARIE has
no Immediate or Indexed Addressing instructions and only two Indirect
Addressing instructions: AddI and JumpI.  (MARIE has no SubI, LoadI,
or StoreI - a real computer ISA would be more consistent and permit
more address modes.)

6.Give the RTL/RTN for a new MARIE LoadI instruction:
    MAR <-- X
    MBR <-- M[MAR]
    MAR <-- MBR
    MBR <-- M[MAR]
    AC  <-- MBR

7.On separate paper, fill in the four-element addressing mode table for
  Question 13, p.277.

    Immediate  1000
    Direct     1400
    Indirect   1300
    Indexed (with R1)  1000

8.On separate paper, fill in the four-element addressing mode table for Question 14, p.277.

    Immediate  500
    Direct     100
    Indirect   600
    Indexed (with R1)  800