-
Notifications
You must be signed in to change notification settings - Fork 2
/
Copy pathGroup4.X68
1898 lines (1391 loc) · 71.5 KB
/
Group4.X68
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
*-----------------------------------------------------------
* Title : Final Project
* Written by : Group 4 - Arkar Kyaw Swar, Siddharth Rao, Phu Thinh Dang
* Date : 06/02/2022
* Description: 68K Disassembler
*-----------------------------------------------------------
STACK EQU $A000
HEXBITS EQU $2760
FIRST_THREE_BITS_AFTER_OPCODE EQU $2770
SECOND_THREE_BITS_AFTER_OPCODE EQU $2780
THIRD_THREE_BITS_AFTER_OPCODE EQU $2790
FOURTH_THREE_BITS_AFTER_OPCODE EQU $2800
DATA_SIZE EQU $2810
CURRENT_ADDR EQU $2820
CR EQU $0D
LF EQU $0A
START: ORG $1000 ; FIRST INSTRUCTION OF THE PROG
LEA STACK, A7 ; SET UP THE SP
*------------ INTRO AND SOME RULES FOR THE DISASSEMBLER -----------------
LEA RULE, A1
MOVE.B #14, D0
TRAP #15
LEA STR_SPACE, A1 * break a line for readability
MOVE.B #13, D0
TRAP #15
*------------ PROMPT THE USER FOR ADDRESSES -----------------
USER_INPUT
CLR.L D1 * NEED TO CLEAR THE PROMPT IF A USER WISHES TO CONTINUE READING A PROGRAM
* STARTING ADDRESS
LEA PROMPT1, A1 * LOAD STARTING ADDRESS PROMPT TO A1
MOVE.B #14, D0 * DISPLAY PROMPT
TRAP #15
LEA EXTRA1, A1 * TO READ IN USER INPUT
MOVE.B #2, D0 * STORE USER INPUT STARTING ADDRESS STRING IN A1
TRAP #15
JSR INPUT_VALID_SIZE ; IF USER ACCIDENTALLY ENTER INVALID SIZE FOR THE INPUT
CMP.L #$FF00, D1 ; CLEARING SCREEN TASK 11
BEQ USER_INPUT ; LOOP BACK TO ASK USER INPUT AGAIN
MOVE.B #0, D0 * TO CHECK WHETHER STARTING OR ENDIND ADDRESS IN SUBROUTINE
JSR CONVERT
JSR AFTER_CONVERT_CHECK * CHECK IF IT IS VALID
CMP.L #$FF00, D1
BEQ USER_INPUT
* ENDING ADDRESS
LEA PROMPT2, A1 * LOAD ENDING ADDRESS PROMPT TO A1
MOVE.B #14, D0 * DISPLAY PROMPT
TRAP #15
LEA EXTRA2, A1 * TO READ IN USER INPUT
MOVE.B #2, D0 * STORE USER INPUT ENDING ADDRESS STRING IN A1
TRAP #15
JSR INPUT_VALID_SIZE ; IF USER ACCIDENTALLY ENTER INVALID SIZE FOR THE INPUT
CMP.L #$FF00, D1 ; CLEARING SCREEN TASK 11
BEQ USER_INPUT
MOVE.B #1, D0 * TO CHECK WHETHER STARTING OR ENDIND ADDRESS IN SUBROUTINE
JSR CONVERT
JSR AFTER_CONVERT_CHECK * CHECK IF IF IT IS VAL
CMP.L #$FF00, D1
BEQ USER_INPUT
CLR.L D2 * COUNTER TO READ 30 LOC AT A TIME
SAGEA_CHECK CMP.L D6, D5 * IF THE ENDING ADDR > STARTING ADDR AT THE 1ST PLACE
BGT NOTIFY
PAGE_SCAN_LOOP
* D5 IS THE STARTING ADDRESS
CMP.L D5, D6 * compare starting addr to ending addr
BLT EXIT_LOOP
CMP.B #$14, D7 * $14 should be 20 In hex
BEQ DISASSAMBLY_20_LOC
MOVE.L #CURR_ADDRESS, A5
MOVE.L D5, D3
MOVE.B #0, (A5)+
JSR DISPLAY
MOVEA.L D5, A2
BRA READ_OPCODE
INCRE_LINE LEA STR_SPACE ,A1
MOVE.B #14,D0
TRAP #15
MOVE.L A2, D5 ;Increment this BY 2
;MOVE.L #$2, StartAddr
ADD.B #1, D7 ;Increment the amount of lines displayed by 1
BRA PAGE_SCAN_LOOP
DISASSAMBLY_20_LOC
CLR.L D7
BRA NEXT_PROMPT
**------------ CONVERT THE ADDRESS STRINGS TO HEXADECIMAL VALUES -----------------
CONVERT CLR.L D3 * TO STORE ASCII VALUES
MOVE.L #0, D2 * LOOP COUNTER
MOVE.L #8, D1 * TERMINAL VALUE
MOVE.L #0, D6 * TO STORE HEXADECIMAL VALUES OF ADDRESSES
CONVERT_LOOP
CMP.L D2, D1 * CHECK TO TERMINATE THE LOOP
BEQ EXIT_CONV_LOOP * BRANCH TO NEXT PART IF ABOVE CONDITION IS MET
MOVE.B (A1)+, D3 * READ A BYTE FROM A1 (A HEXADECIMAL DIGIT)
CMP.B #$39, D3 * IF IT IS A LETTER OR NUMBER
BGT LETTER_CONVERT * LETTER
BLE NUMBER_CONVERT * NUMBER
LETTER_CONVERT
CMP.B #$46, D3 * if it is greater than F -> Invalid
BGT INVALID_HEX_STRING
CMP.B #$41,D3 * IF ASCII CODE IS [41,46] , IT IS A LETTER
BGE ASCII_TO_LETTER * IF SO, BRANCH TO LETTER CONVERTER
BLT INVALID_HEX_STRING ; IF it is less than A, it's invalid
; NUMBER CHECK. SHOULD BE [0-9]
NUMBER_CONVERT
CMP.B #$30,D3 * LESS THAN 0-> INVALID
BLT INVALID_HEX_STRING
CMP.B #$39,D3 * IF ASCII CODE IS < $3A, IT IS A NUMBER
BGT INVALID_HEX_STRING * GREATER THAN 9 -> INVALID
BLE ASCII_TO_NUM * IF SO, BRANCH TO NUMBER CONVERTER
ASCII_TO_LETTER SUB.B #$37,D3 * CONVERT TO LETTER
BRA SHIFT_AND_ADD
ASCII_TO_NUM SUB.B #$30,D3 * CONVERT TO NUM
SHIFT_AND_ADD LSL.L #4, D6 * SHIFT
ADD.B D3, D6 * ADD TO CURRENT VALUE
CMPI.B #7, D2 * ACCESS THE LAST BIT TO CHECK THE INPUT IS EVEN OR ODD
BEQ EVEN_OR_ODD
BRA CONT
CONT ADDQ.L #1, D2
BRA CONVERT_LOOP
INVALID_HEX_STRING
LEA CANT_CONVERT, A1
MOVE.B #14, D0
TRAP #15
BRA TRY_AGAIN_PROMPT
EXIT_CONV_LOOP CMP.B #0, D0
BNE RETURN
MOVE.L D6, D5
RTS
EVEN_OR_ODD
BTST.L #00, D6 ; ACCESS THE LAST BIT
BNE ODD ; LAST BIT IS 1 -> ODD
BRA EXIT_CONV_LOOP
ODD LEA ODD_NUMBER, A1
MOVE.B #14, D0
TRAP #15
BRA TRY_AGAIN_PROMPT
RETURN RTS
AFTER_CONVERT_CHECK
CMP.L #$00001000, D5 * NEED TO DOUBLE CHECK THIS
BLT LESS_THAN_START
CMP.L #$00FFFFF0, D5
BGT GREATER_END
RTS
LESS_THAN_START
LEA LESS_START, A1 * ENTERED NUMBER < START
MOVE.B #14, D0
TRAP #15
BRA TRY_AGAIN_PROMPT
GREATER_END
LEA MORE_END, A1 * ENTERED NUMBER > END
MOVE.B #14, D0
TRAP #15
BRA TRY_AGAIN_PROMPT
*-----------------------20 lines of code at a time ------------------------------------
NEXT_PROMPT
LEA PROMPT3, A1
MOVE.B #14, D0
TRAP #15
MOVE.B #5, D0 * READ THE SINGLE CHARACTER FROM KB
TRAP #15
LEA STR_SPACE, A1
MOVE.B #14, D0
TRAP #15
CMP.B #$4E, D1 * "N" IN ASCII
BEQ ENDING
CMP.B #$6E, D1 * "n" in ascii
BEQ ENDING
CMP.B #$D, D1 * PRESS ENTER
BEQ NEXT_PAGE
LEA ENTER_OR_N, A1 ; NOTICE USER FOR ERROR INPUT
MOVE.B #14, D1
TRAP #15
BRA NEXT_PROMPT ; LOOP BACK TO ASK
NEXT_PAGE
MOVE.W #$FF00, D1 * TO CLEAR THE SCREEN
MOVE.B #11, D0
TRAP #15
BRA PAGE_SCAN_LOOP
*----------------- PRINT OUT THE CURRENT ADDRESS -------------------------------
DISPLAY
LEA CURR_ADDRESS, A1 * DISPLAY CURRENT ADDRESS
MOVE.B #14, D0
TRAP #15
RTS
CLR_SCREEN
MOVE.W #$FF00, D1 * TO CLR SCREEN FOR TASK 11
MOVE.B #11, D0
TRAP #15
RTS
* Here, we have starting address in D5 and ending address in D6 as hexadecimals
*----------------- READ OPCODE: MAIN LOOP -------------------------------
MAIN MOVEA.L D5, A2 * START READING FROM D5(STARTING ADDRESS)
READ_OPCODE
CLR.L D3 * WE WILL STORE EACH WORD FROM CURRENT INSTRUCTION IN D3
CMP.W A2, D6
BLT EXIT_MAIN_LOOP
JSR PRINT_MEM_ADDR
JSR PRINT_SPACE
MOVE.L A2, CURRENT_ADDR
MOVE.W (A2)+, D3 * RETRIEVE OPCODE OF CURRENT INSTRUCTION
*------------------------- DECODE OPCODE -----------------------------------
MOVE.W D3, HEXBITS * MOVE D3 INTO HEXBITS
LSR.W #4, D3 * SHIFT WORD INSTRUCTION (IN D3) BY 4 BITS
LSR.W #4, D3 * SHIFT WORD INSTRUCTION (IN D3) BY 4 BITS
LSR.W #4, D3 * SHIFT WORD INSTRUCTION (IN D3) BY 4 BITS
* D3 SHOULD NOW CONTAIN ONLY THE FIRST 4 BITS OF THE WORD (MOST OPCODES)
CMP.B #%1101, D3 * COMPARE 4 BITS OF WORD TO ADD OPCODE (1101)
BEQ ADD_ADDA_OPCODE * IF EQUAL GO TO ADD_ADDA_OPCODE
CMP.B #%0101, D3 * COMPARE 4 BITS OF WORD TO ADD OPCODE (0101)
BEQ ADDQ_OPCODE * IF EQUAL GO TO ADDQ_OPCODE
CMP.B #%1011, D3 * COMPARE 4 BITS OF WORD TO CMP OPCODE (1011)
BEQ CMP_OPCODE * IF EQUAL GO TO CMP_OPCODE
CMP.B #%1000, D3 * COMPARE 4 BITS OF WORD TO OR OPCODE (1000)
BEQ OR_OPCODE * IF EQUAL GO TO OR_OPCODE
CMP.B #%1001, D3 * COMPARE 4 BITS OF WORD TO SUB OPCODE (1001)
BEQ SUB_OPCODE * IF EQUAL GO TO SUB_OPCODE
CMP.B #%1100, D3 * COMPARE 4 BITS OF WORD TO ADD OPCODE (1100)
BEQ AND_OPCODE * IF EQUAL GO TO AND_OPCODE
CMP.B #%0001, D3 * COMPARE 4 BITS OF WORD TO MOVE.B OPCODE (0001)
BEQ MOVEB_OPCODE * IF EQUAL GO TO MOVEB_OPCODE
CMP.B #%0111, D3 * COMPARE 4 BITS OF THE WORD TO MOVEQ OPCODE (0111)
BEQ MOVEQ_OPCODE * IF EQUAL GO TO MOVEQ_OPCODE
CMP.B #%0011, D3 * COMPARE 4 BITS OF THE WORD TO MOVEW/MOVEAW OPCODE (0011)
BEQ MOVEW_MOVEAW_OPCODE * IF EQUAL GO TO MOVEW_MOVEAW_OPCODE
CMP.B #%0010, D3 * COMPARE 4 BITS OF THE WORD TO MOVEL/MOVEAL OPCODE (0010)
BEQ MOVEL_MOVEAL_OPCODE * IF EQUAL GO TO MOVEL_MOVEAL_OPCODE
CMP.B #%0110, D3 * COMPARE 4 BITS OF THE WORD TO BCC OPCODE (0110)
BEQ BCC_BRA_OPCODE * IF EQUAL GO TO BCC_BRA_OPCODE
CMP.B #%0100, D3 * COMPARE 4 BITS OF WORD TO LEA/NOP/JSR/RTS/ OPCODE (0100)
BEQ LEA_NOP_NOT_JSR_RTS_OPCODE * IF EQUAL GO TO LEA_NOP_NOT_JSR_RTS_OPCODE
CMP.B #%1110, D3 * COMPARE 4 BITS OF THE WORD TO LSL/ASR OPCODE (1110)
BEQ LSL_LSR_ASL_ASR_ROL_ROR_OPCODE * IF EQUAL GO TO LSL_LSR_ASL_ASR_ROL_ROR_OPCODE
JSR INVALID_OPCODE * IF NOT EQUAL TO ABOVE OPCODE, ASSUME INVALID OPCODE/DATA
ADD_ADDA_OPCODE
JSR SPLIT_AFTER_OPCODE
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%011, D3
BEQ ADDA_OPCODE
CMP.B #%111, D3
BEQ ADDA_OPCODE
CMP.B #%000, D3
BEQ ADD_OPCODE
CMP.B #%001, D3
BEQ ADD_OPCODE
CMP.B #%010, D3
BEQ ADD_OPCODE
CMP.B #%100, D3
BEQ ADD_OPCODE
CMP.B #%101, D3
BEQ ADD_OPCODE
CMP.B #%110, D3
BEQ ADD_OPCODE
BRA INVALID_OPCODE
ADD_OPCODE
LEA ADD_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SIZE_CODE
JSR PRINT_SPACE
BRA P_ADD_EA
ADDA_OPCODE
LEA ADDA_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_ADDA_SIZE_CODE
JSR PRINT_SPACE
BRA P_ADDA_EA
ADDQ_OPCODE
LEA ADDQ_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR SPLIT_AFTER_OPCODE
JSR PRINT_SIZE_CODE
JSR PRINT_SPACE
MOVE.W HEXBITS, D3
BRA P_ADDQ_EA
CMP_OPCODE
LEA CMP_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR SPLIT_AFTER_OPCODE
JSR PRINT_SIZE_CODE
JSR PRINT_SPACE
BRA P_CMP_EA
OR_OPCODE
LEA OR_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR SPLIT_AFTER_OPCODE
JSR PRINT_SIZE_CODE
JSR PRINT_SPACE
BRA P_AND_OR_EA
SUB_OPCODE
LEA SUB_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR SPLIT_AFTER_OPCODE
JSR PRINT_SIZE_CODE
JSR PRINT_SPACE
BRA P_SUB_EA
AND_OPCODE
LEA AND_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR SPLIT_AFTER_OPCODE
JSR PRINT_SIZE_CODE
JSR PRINT_SPACE
BRA P_AND_OR_EA
MOVEB_OPCODE
LEA MOVEB_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR SPLIT_AFTER_OPCODE
JSR PRINT_SPACE
BRA P_MOVEB_EA
MOVEQ_OPCODE
LEA MOVEQ_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR SPLIT_AFTER_OPCODE
JSR PRINT_SPACE
BRA P_MOVEQ_EA
MOVEW_MOVEAW_OPCODE
JSR SPLIT_AFTER_OPCODE
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%001, D3
BEQ MOVEAW_OPCODE
LEA MOVEW_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_MOVEW_EA
MOVEAW_OPCODE
LEA MOVEAW_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_MOVEAW_EA
MOVEL_MOVEAL_OPCODE
JSR SPLIT_AFTER_OPCODE
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%001, D3
BEQ MOVEAL_OPCODE
LEA MOVEL_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_MOVEL_EA
MOVEAL_OPCODE
LEA MOVEAL_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_MOVEAL_EA
BCC_BRA_OPCODE
ADD.L #$2, CURRENT_ADDR *PC VALUE
MOVE.W HEXBITS, D3
LSL #4, D3
LSR #4, D3
LSR #4, D3
LSR #4, D3
CMP.B #%0000, D3
BEQ BRA_OPCODE
CMP.B #%0111, D3
BEQ BEQ_OPCODE
CMP.B #%1110, D3
BEQ BGT_OPCODE
CMP.B #%1111, D3
BEQ BLE_OPCODE
BRA INVALID_OPCODE
BRA_OPCODE
LEA BRA_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_BCC_BRA_EA
BEQ_OPCODE
LEA BEQ_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_BCC_BRA_EA
BGT_OPCODE
LEA BGT_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_BCC_BRA_EA
BLE_OPCODE
LEA BLE_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_BCC_BRA_EA
LEA_NOP_NOT_JSR_RTS_OPCODE
JSR SPLIT_AFTER_OPCODE
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%001, D3
BEQ NOP_NOTW_RTS_OPCODE
CMP.B #%111, D3
BEQ LEA_OPCODE
CMP.B #%000, D3
BEQ NOTB_OPCODE
CMP.B #%010, D3
BEQ NOTL_JSR_OPCODE
BRA INVALID_OPCODE
NOP_NOTW_RTS_OPCODE
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%111, D3
BEQ NOP_RTS_OPCODE
CMP.B #%011, D3
BEQ NOTW_OPCODE
BRA INVALID_OPCODE
NOP_RTS_OPCODE
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%001, D3
BEQ NOP_OPCODE
CMP.B #%101, D3
BEQ RTS_OPCODE
BRA INVALID_OPCODE
NOP_OPCODE
LEA NOP_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_NOP_RTS_EA
RTS_OPCODE
LEA RTS_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_NOP_RTS_EA
NOTW_OPCODE
LEA NOTW_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_NOT_JSR_EA
LEA_OPCODE
LEA LEA_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_LEA_EA
NOTB_OPCODE
LEA NOTB_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_NOT_JSR_EA
NOTL_JSR_OPCODE
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%111, D3
BEQ JSR_OPCODE
CMP.B #%011, D3
BEQ NOTL_OPCODE
BRA INVALID_OPCODE
JSR_OPCODE
LEA JSR_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_NOT_JSR_EA
NOTL_OPCODE
LEA NOTL_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_NOT_JSR_EA
LSL_LSR_ASL_ASR_ROL_ROR_OPCODE
JSR SPLIT_AFTER_OPCODE
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, D3
LSL #6,D3
LSL #8,D3
LSR #6,D3
LSR #8,D3
CMP.B #%11, D3
BEQ ADDR_SHIFT
CMP.B #%00, D3
BEQ REGISTER_SHIFT
CMP.B #%01, D3
BEQ REGISTER_SHIFT
CMP.B #%10, D3
BEQ REGISTER_SHIFT
BRA INVALID_OPCODE
REGISTER_SHIFT
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D3
LSL #6,D3
LSL #8,D3
LSR #6,D3
LSR #8,D3
CMP.B #%01, D3
BEQ REGISTER_LSL_LSR_OPCODE
CMP.B #%00, D3
BEQ REGISTER_ASL_ASR_OPCODE
CMP.B #%11, D3
BEQ REGISTER_ROL_ROR_OPCODE
BRA INVALID_OPCODE
REGISTER_LSL_LSR_OPCODE
LEA LS_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_DIRECTION
JSR PRINT_SHIFT_SIZE_CODE
JSR PRINT_SPACE
BRA P_LSL_LSR_ASL_ASR_ROL_ROR_EA
REGISTER_ASL_ASR_OPCODE
LEA AS_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_DIRECTION
JSR PRINT_SHIFT_SIZE_CODE
JSR PRINT_SPACE
BRA P_LSL_LSR_ASL_ASR_ROL_ROR_EA
REGISTER_ROL_ROR_OPCODE
LEA RO_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_DIRECTION
JSR PRINT_SHIFT_SIZE_CODE
JSR PRINT_SPACE
BRA P_LSL_LSR_ASL_ASR_ROL_ROR_EA
ADDR_SHIFT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D3
CMP.B #%000, D3
BEQ ADDR_ASL_ASR_OPCODE
CMP.B #%001, D3
BEQ ADDR_LSL_LSR_OPCODE
CMP.B #%011, D3
BEQ ADDR_ROL_ROR_OPCODE
BRA INVALID_OPCODE
ADDR_LSL_LSR_OPCODE
LEA LS_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_DIRECTION
JSR PRINT_SPACE
BRA P_ADDR_SHIFT_EA
ADDR_ASL_ASR_OPCODE
LEA AS_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_DIRECTION
JSR PRINT_SPACE
BRA P_ADDR_SHIFT_EA
ADDR_ROL_ROR_OPCODE
LEA RO_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_DIRECTION
JSR PRINT_SPACE
BRA P_ADDR_SHIFT_EA
INVALID_OPCODE
LEA INVALID_OPCODE_STRING, A1
MOVE.B #14, D0
TRAP #15
JSR PRINT_SPACE
BRA P_INVALID_EA
*------------------------------- EA ----------------------------------------
P_INVALID_EA
LEA Dollar_sign, A1
MOVE.B #14, D0
TRAP #15
MOVE.W HEXBITS, D3
JSR HEX_TO_STRING
BRA INSTRUC_DONE
P_ADD_EA
CMP.B #1, D2 * CHECK WHICH OPMODE
BEQ P_ADD_DnFIRST_EA * Dn + < ea > -> < ea >
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1 * EA MODE , <EA> + Dn -> Dn
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
JSR COMMA_PRINT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
BRA INSTRUC_DONE
P_ADD_DnFIRST_EA * Dn + < ea > -> < ea >
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
JSR COMMA_PRINT
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
BRA INSTRUC_DONE
P_ADDA_EA * ADDA <EA>, AN
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
JSR COMMA_PRINT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR An_Mode_Print
BRA INSTRUC_DONE
P_ADDQ_EA
LEA Hash_sign, a1
MOVE.B #14, D0
TRAP #15
CLR.L D1
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D1
CMP.W #%0000, D1 * IF THE DATA IS %000, IT'S 8 (%1000).
BEQ ADDQ_OVERFLOW
OVERFLOWA_FIXED JSR PRINT_IMMEDIATE
JSR COMMA_PRINT
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
JSR EA_MODE_TABLE
BRA INSTRUC_DONE
ADDQ_OVERFLOW
MOVE.W #%1000, D1
BRA OVERFLOWA_FIXED
P_CMP_EA
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
JSR COMMA_PRINT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
BRA INSTRUC_DONE
P_SUB_EA
CMP.B #1, D2 * CHECK WHICH OPMODE
BEQ P_SUB_DnFIRST_EA * SUB OPMODE => EA - Dn -> EA
* IF DIDN'T BRANCH, SUB OPMODE => Dn - EA -> Dn
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
JSR COMMA_PRINT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
BRA INSTRUC_DONE
P_SUB_DnFIRST_EA
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
JSR COMMA_PRINT
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
BRA INSTRUC_DONE
P_AND_OR_EA
CMP.B #1, D2 * CHECK WHICH OPMODE
BEQ P_AND_OR_DnFIRST_EA * AND OPMODE => Dn /\ EA -> EA
* IF DIDN'T BRANCH, AND OPMODE => EA /\ Dn -> Dn
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
JSR COMMA_PRINT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
BRA INSTRUC_DONE
P_AND_OR_DnFIRST_EA
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
JSR COMMA_PRINT
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, DATA_SIZE
JSR EA_MODE_TABLE
BRA INSTRUC_DONE
P_MOVEB_EA * MOVE <EA>, <EA>
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W #%0001, DATA_SIZE
JSR EA_MODE_TABLE
JSR COMMA_PRINT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
MOVE.W SECOND_THREE_BITS_AFTER_OPCODE, D1
JSR EA_MODE_TABLE
BRA INSTRUC_DONE
P_MOVEQ_EA
LEA Hash_sign, a1
MOVE.B #14, D0
TRAP #15
MOVE.W HEXBITS, D3
CLR.L D1
MOVE.B D3, D1
JSR PRINT_IMMEDIATE
JSR COMMA_PRINT
MOVE.W FIRST_THREE_BITS_AFTER_OPCODE, D4
JSR Dn_Mode_Print
BRA INSTRUC_DONE
P_MOVEW_EA
MOVE.W THIRD_THREE_BITS_AFTER_OPCODE, D1
MOVE.W FOURTH_THREE_BITS_AFTER_OPCODE, D4
MOVE.W #%0011, DATA_SIZE
JSR EA_MODE_TABLE
JSR COMMA_PRINT