git @ Cat's Eye Technologies linapple / master src / CPU.cpp
master

Tree @master (Download .tar.gz)

CPU.cpp @masterraw · history · blame

   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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
/*
AppleWin : An Apple //e emulator for Windows

Copyright (C) 1994-1996, Michael O'Brien
Copyright (C) 1999-2001, Oliver Schmidt
Copyright (C) 2002-2005, Tom Charlesworth
Copyright (C) 2006-2007, Tom Charlesworth, Michael Pohoreski

AppleWin is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

AppleWin is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with AppleWin; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

// #define UPDATE_ALL_PER_CYCLE

/* Description: 6502/65C02 emulation
 *
 * Author: Various
 */

// TO DO:
// . All these CPP macros need to be converted to inline funcs

// TeaRex's Note about illegal opcodes:
// ------------------------------------
// . I've followed the names and descriptions given in
// . "Extra Instructions Of The 65XX Series CPU"
// . by Adam Vardy, dated Sept 27, 1996.
// . The exception is, what he calls "SKB" and "SKW" I call "NOP",
// . for consistency's sake. Several other naming conventions exist.
// . Of course, only the 6502 has illegal opcodes, the 65C02 doesn't.
// . Thus they're not emulated in Enhanced //e g_nAppMode. Games relying on them
// . don't run on a real Enhanced //e either. The old mixture of 65C02
// . emulation and skipping the right number of bytes for illegal 6502
// . opcodes, while working surprisingly well in practice, was IMHO
// . ill-founded in theory and has thus been removed.


// Note about bSlowerOnPagecross:
// -------------------
// . This is used to determine if a cycle needs to be added for a page-crossing.
//
// Modes that are affected:
// . ABS,X; ABS,Y; (IND),Y
//
// The following opcodes (when indexed) add a cycle if page is crossed:
// . ADC, AND, Bxx, CMP, EOR, LDA, LDX, LDY, ORA, SBC
// . NB. Those opcode that DO NOT write to memory.
// . 65C02: JMP (ABS-INDIRECT): 65C02 fixes JMP ($xxFF) bug but needs extra cycle in that case
// . 65C02: JMP (ABS-INDIRECT,X): Probably. Currently unimplemented.
//
// The following opcodes (when indexed)   DO NOT add a cycle if page is crossed:
// . ASL, DEC, INC, LSR, ROL, ROR, STA, STX, STY
// . NB. Those opcode that DO write to memory.
//
// What about these:
// . 65C02: STZ?, TRB?, TSB?
// . Answer: TRB & TSB don't have affected adressing modes
// .         STZ probably doesn't add a cycle since otherwise it would be slower than STA which doesn't make sense.
//
// NB. 'Zero-page indexed' opcodes wrap back to zero-page.
// .   The same goes for all the zero-page indirect modes.
//
// NB2. bSlowerOnPagecross can't be used for r/w detection, as these
// .    opcodes don't init this flag:
// . $EC CPX ABS (since there's no addressing g_nAppMode of CPY which has variable cycle number)
// . $CC CPY ABS (same)
//
// 65C02 info:
// .  Read-modify-write instructions abs indexed in same page take 6 cycles (cf. 7 cycles for 6502)
// .  ASL, DEC, INC, LSR, ROL, ROR
// .  This should work now (but makes bSlowerOnPagecross even less useful for r/w detection)
//
// . Thanks to Scott Hemphill for the verified CMOS ADC and SBC algorithm! You rock.
// . And thanks to the VICE team for the NMOS ADC and SBC algorithms as well as the
// . algorithms for those illops which involve ADC or SBC. You rock too.

// remained for future debugging...??

/* Adaptation for SDL and POSIX (l) by beom beotiger, Nov-Dec 2007 */

#include "stdafx.h"
#include "MouseInterface.h"
#include "Debug.h"
#include <assert.h>

// for CRITICAL_SECTION handling
#include <pthread.h>

#define   AF_SIGN       0x80
#define   AF_OVERFLOW   0x40
#define   AF_RESERVED   0x20
#define   AF_BREAK      0x10
#define   AF_DECIMAL    0x08
#define   AF_INTERRUPT  0x04
#define   AF_ZERO       0x02
#define   AF_CARRY      0x01

#define   SHORTOPCODES  22
#define   BENCHOPCODES  33

// What is this 6502 code?
static BYTE benchopcode[BENCHOPCODES] = {0x06,0x16,0x24,0x45,0x48,0x65,0x68,0x76,
          0x84,0x85,0x86,0x91,0x94,0xA4,0xA5,0xA6,
          0xB1,0xB4,0xC0,0xC4,0xC5,0xE6,
          0x19,0x6D,0x8D,0x99,0x9D,0xAD,0xB9,0xBD,
          0xDD,0xED,0xEE};

regsrec regs;
unsigned __int64 g_nCumulativeCycles = 0;

static ULONG g_nCyclesSubmitted;  // Number of cycles submitted to CpuExecute()
static ULONG g_nCyclesExecuted;

static signed long g_uInternalExecutedCycles;
// TODO: Use IRQ_CHECK_TIMEOUT=128 when running at full-speed else with IRQ_CHECK_TIMEOUT=1
// - What about when running benchmark?
// GPH Dropped to IRQ_CHECK_TIMOUT=16 - Mockingboard-intensive applications sound
// "jerky" at 128.  Does not show appreciable CPU impact in top CPU profiler.
static const int IRQ_CHECK_TIMEOUT = 16;
static signed int g_nIrqCheckTimeout = IRQ_CHECK_TIMEOUT;

//

// Assume all interrupt sources assert until the device is told to stop:
// - eg by r/w to device's register or a machine reset

static bool g_bCritSectionValid = false;  // Deleting CritialSection when not valid causes crash on Win98
//static CRITICAL_SECTION g_CriticalSection;  // To guard /g_bmIRQ/ & /g_bmNMI/
pthread_mutex_t g_CriticalSection = PTHREAD_MUTEX_INITIALIZER;
static volatile UINT32 g_bmIRQ = 0;
static volatile UINT32 g_bmNMI = 0;
static volatile BOOL g_bNmiFlank = FALSE; // Positive going flank on NMI line

/****************************************************************************
*
*  GENERAL PURPOSE MACROS
*
***/

#define AF_TO_EF  flagc = (regs.ps & AF_CARRY);            \
      flagn = (regs.ps & AF_SIGN);            \
      flagv = (regs.ps & AF_OVERFLOW);          \
      flagz = (regs.ps & AF_ZERO);
#define EF_TO_AF  regs.ps = (regs.ps & ~(AF_CARRY | AF_SIGN |        \
           AF_OVERFLOW | AF_ZERO))      \
            | flagc               \
            | flagn              \
            | (flagv ? AF_OVERFLOW : 0)        \
            | (flagz ? AF_ZERO     : 0)        \
            | AF_RESERVED | AF_BREAK;
// CYC(a): This can be optimised, as only certain opcodes will affect uExtraCycles
#define CYC(a)   uExecutedCycles += (a)+uExtraCycles; g_nIrqCheckTimeout -= (a)+uExtraCycles;
#define POP   (*(mem+((regs.sp >= 0x1FF) ? (regs.sp = 0x100) : ++regs.sp)))
#define PUSH(a)   *(mem+regs.sp--) = (a);            \
     if (regs.sp < 0x100)              \
       regs.sp = 0x1FF;
#define READ   (                  \
        ((addr & 0xF000) == 0xC000)            \
        ? IORead[(addr>>4) & 0xFF](regs.pc,addr,0,0,uExecutedCycles) \
      : *(mem+addr)              \
     )
#define SETNZ(a) {                  \
       flagn = ((a) & 0x80);            \
       flagz = !((a) & 0xFF);              \
     }
#define SETZ(a)   flagz = !((a) & 0xFF);
#define WRITE(a) {                  \
       memdirty[addr >> 8] = 0xFF;            \
       LPBYTE page = memwrite[addr >> 8];        \
       if (page)                \
         *(page+(addr & 0xFF)) = (BYTE)(a);          \
       else if ((addr & 0xF000) == 0xC000)          \
         IOWrite[(addr>>4) & 0xFF](regs.pc,addr,1,(BYTE)(a),uExecutedCycles); \
     }

//

// ExtraCycles:
// +1 if branch taken
// +1 if page boundary crossed
#define BRANCH_TAKEN {          \
       base = regs.pc;    \
       regs.pc += addr;    \
       if ((base ^ regs.pc) & 0xFF00) \
           uExtraCycles=2;    \
       else        \
           uExtraCycles=1;    \
         }

//
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#pragma GCC diagnostic ignored "-Wsequence-point"
#define CHECK_PAGE_CHANGE  if (bSlowerOnPagecross) {          \
             if ((base ^ addr) & 0xFF00)    \
           uExtraCycles=1;        \
         }

/****************************************************************************
*
*  ADDRESSING MODE MACROS
*
***/

#define ABS   addr = *(LPWORD)(mem+regs.pc);   regs.pc += 2;
#define IABSX    addr = *(LPWORD)(mem+(*(LPWORD)(mem+regs.pc))+(WORD)regs.x); regs.pc += 2;
#define ABSX   base = *(LPWORD)(mem+regs.pc); addr = base+(WORD)regs.x; regs.pc += 2; CHECK_PAGE_CHANGE;
#define ABSY   base = *(LPWORD)(mem+regs.pc); addr = base+(WORD)regs.y; regs.pc += 2; CHECK_PAGE_CHANGE;
#define IABSCMOS base = *(LPWORD)(mem+regs.pc);                            \
     addr = *(LPWORD)(mem+base);                      \
     if ((base & 0xFF) == 0xFF) uExtraCycles=1;      \
     regs.pc += 2;
#define IABSNMOS base = *(LPWORD)(mem+regs.pc);                            \
     if ((base & 0xFF) == 0xFF)          \
           addr = *(mem+base)+((WORD)*(mem+(base&0xFF00))<<8);\
       else                                                   \
           addr = *(LPWORD)(mem+base);                        \
     regs.pc += 2;
#define IMM   addr = regs.pc++;
#define INDX   base = ((*(mem+regs.pc++))+regs.x) & 0xFF;          \
     if (base == 0xFF)                                   \
         addr = *(mem+0xFF)+(((WORD)*mem)<<8);           \
     else                                                \
         addr = *(LPWORD)(mem+base);
#define INDY   if (*(mem+regs.pc) == 0xFF)                         \
         base = *(mem+0xFF)+(((WORD)*mem)<<8);           \
     else                                                \
         base = *(LPWORD)(mem+*(mem+regs.pc));           \
     regs.pc++;                                          \
     addr = base+(WORD)regs.y;                           \
     CHECK_PAGE_CHANGE;
#define IZPG   base = *(mem+regs.pc++);                            \
     if (base == 0xFF)                                   \
         addr = *(mem+0xFF)+(((WORD)*mem)<<8);           \
     else                                                \
         addr = *(LPWORD)(mem+base);
#define REL   addr = (signed char)*(mem+regs.pc++);

// Optimiation note:
// . Opcodes that generate zero-page addresses can't be accessing $C000..$CFFF
//   so they could be paired with special READZP/WRITEZP macros (instead of READ/WRITE)
#define ZPG   addr = *(mem+regs.pc++);
#define ZPGX   addr = ((*(mem+regs.pc++))+regs.x) & 0xFF;
#define ZPGY   addr = ((*(mem+regs.pc++))+regs.y) & 0xFF;

/****************************************************************************
*
*  INSTRUCTION MACROS
*
***/

#define ADC_NMOS bSlowerOnPagecross = 1;                \
     temp = READ;                \
     if (regs.ps & AF_DECIMAL) {            \
       val    = (regs.a & 0x0F) + (temp & 0x0F) + flagc;      \
       if (val > 0x09)              \
         val += 0x06;              \
       if (val <= 0x0F)              \
         val = (val & 0x0F) + (regs.a & 0xF0) + (temp & 0xF0);  \
       else                  \
         val = (val & 0x0F) + (regs.a & 0xF0) + (temp & 0xF0) + 0x10;\
       flagz = !((regs.a + temp + flagc) & 0xFF);        \
       flagn = (val & 0x80);            \
       flagv = ((regs.a ^ val) & 0x80) && !((regs.a ^ temp) & 0x80);\
       if ((val & 0x1F0) > 0x90)            \
         val += 0x60;              \
       flagc = ((val & 0xFF0) > 0xF0);          \
       regs.a = val & 0xFF;                                     \
      }                  \
     else {                  \
       val    = regs.a + temp + flagc;          \
       flagc  = (val > 0xFF);            \
       flagv  = (((regs.a & 0x80) == (temp & 0x80)) &&      \
           ((regs.a & 0x80) != (val & 0x80)));      \
       regs.a = val & 0xFF;              \
       SETNZ(regs.a);              \
     }
#define ADC_CMOS bSlowerOnPagecross = 1;                \
                 temp = READ;                \
                 flagv = !((regs.a ^ temp) & 0x80);          \
     if (regs.ps & AF_DECIMAL) {            \
        uExtraCycles++;              \
        val = (regs.a & 0x0f) + (temp & 0x0f) + flagc;          \
        if (val >= 0x0A)              \
           val = 0x10 | ((val + 6) & 0x0f);          \
        val += (regs.a & 0xf0) + (temp & 0xf0);        \
        if (val >= 0xA0) {              \
           flagc = 1;              \
           if (val >= 0x180)            \
        flagv = 0;              \
           val += 0x60;              \
        }                  \
        else {                \
           flagc = 0;              \
           if (val < 0x80)              \
              flagv = 0;              \
        }                  \
     }                  \
     else {                  \
        val = regs.a + temp + flagc;                            \
        if (val >= 0x100) {              \
           flagc = 1;              \
           if (val >= 0x180) flagv = 0;          \
        }                  \
        else {                \
           flagc = 0;              \
           if (val < 0x80) flagv = 0;          \
        }                  \
     }                  \
     regs.a = val & 0xFF;              \
     SETNZ(regs.a)
#define ALR   regs.a &= READ;              \
     flagc = (regs.a & 1);              \
     flagn = 0;                \
     regs.a >>= 1;                \
     SETZ(regs.a)
#define AND   bSlowerOnPagecross = 1;                \
     regs.a &= READ;              \
     SETNZ(regs.a)
#define ANC   regs.a &= READ;              \
     SETNZ(regs.a)                \
     flagc = !!flagn;
#define ARR   temp = regs.a & READ; /* Yes, this is sick */        \
     if (regs.ps & AF_DECIMAL) {            \
       val = temp;                \
       val |= (flagc ? 0x100 : 0);            \
       val >>= 1;                \
       flagn = (flagc ? 0x80 : 0);              \
       SETZ(val)                \
       flagv = ((val ^ temp) & 0x40);          \
       if (((val & 0x0F) + (val & 0x01)) > 0x05)                \
         val = (val & 0xF0) | ((val + 0x06) & 0x0F);      \
       if (((val & 0xF0) + (val & 0x10)) > 0x50) {        \
         val = (val & 0x0F) | ((val + 0x60) & 0xF0);      \
         flagc = 1;                \
       }                  \
       else                  \
         flagc = 0;                \
       regs.a = (val & 0xFF);            \
     }                  \
     else {                  \
       val = temp | (flagc ? 0x100 : 0);          \
       val >>= 1;                \
       SETNZ(val)                \
       flagc = !!(val & 0x40);            \
       flagv = ((val & 0x40) ^ ((val & 0x20) << 1));      \
       regs.a = (val & 0xFF);            \
     }
#define ASL_NMOS bSlowerOnPagecross = 0;                \
     val   = READ << 1;              \
     flagc = (val > 0xFF);              \
     SETNZ(val)                \
     WRITE(val)
#define ASL_CMOS bSlowerOnPagecross = 1;                \
     val   = READ << 1;              \
     flagc = (val > 0xFF);              \
     SETNZ(val)                \
     WRITE(val)
#define ASLA   val   = regs.a << 1;              \
     flagc = (val > 0xFF);              \
     SETNZ(val)                \
     regs.a = (BYTE)val;
#define ASO   bSlowerOnPagecross = 0;                \
     val   = READ << 1;              \
     flagc = (val > 0xFF);              \
     WRITE(val)                \
     regs.a |= val;                \
     SETNZ(regs.a)
#define AXA   bSlowerOnPagecross = 0;/*FIXME: $93 case is still unclear*/      \
     val = regs.a & regs.x & (((base >> 8) + 1) & 0xFF);      \
     WRITE(val)
#define AXS   bSlowerOnPagecross = 0;                \
     WRITE(regs.a & regs.x)
#define BCC   if (!flagc) BRANCH_TAKEN;
#define BCS   if ( flagc) BRANCH_TAKEN;
#define BEQ   if ( flagz) BRANCH_TAKEN;
#define BIT   bSlowerOnPagecross = 1;                \
     val   = READ;                \
     flagz = !(regs.a & val);            \
     flagn = val & 0x80;              \
     flagv = val & 0x40;
#define BITI   flagz = !(regs.a & READ);
#define BMI   if ( flagn) BRANCH_TAKEN;
#define BNE   if (!flagz) BRANCH_TAKEN;
#define BPL   if (!flagn) BRANCH_TAKEN;
#define BRA   BRANCH_TAKEN;
#define BRK   regs.pc++;                \
     PUSH(regs.pc >> 8)              \
     PUSH(regs.pc & 0xFF)              \
     EF_TO_AF                \
     PUSH(regs.ps);                \
     regs.ps |= AF_INTERRUPT;            \
     regs.pc = *(LPWORD)(mem+0xFFFE);
#define BVC   if (!flagv) BRANCH_TAKEN;
#define BVS   if ( flagv) BRANCH_TAKEN;
#define CLC   flagc = 0;
#define CLD   regs.ps &= ~AF_DECIMAL;
#define CLI   regs.ps &= ~AF_INTERRUPT;
#define CLV   flagv = 0;
#define CMP   bSlowerOnPagecross = 1;                \
     val   = READ;                \
     flagc = (regs.a >= val);            \
     val   = regs.a-val;              \
     SETNZ(val)
#define CPX   val   = READ;                \
     flagc = (regs.x >= val);            \
     val   = regs.x-val;              \
     SETNZ(val)
#define CPY   val   = READ;                \
     flagc = (regs.y >= val);            \
     val   = regs.y-val;              \
     SETNZ(val)
#define DCM   bSlowerOnPagecross = 0;                \
     val = READ-1;                \
     WRITE(val)                \
     flagc = (regs.a >= val);            \
     val   = regs.a-val;              \
     SETNZ(val)
#define DEA   --regs.a;                \
     SETNZ(regs.a)
#define DEC_NMOS bSlowerOnPagecross = 0;                \
     val = READ-1;                \
     SETNZ(val)                \
     WRITE(val)
#define DEC_CMOS bSlowerOnPagecross = 1;                \
     val = READ-1;                \
     SETNZ(val)                \
     WRITE(val)
#define DEX   --regs.x;                \
     SETNZ(regs.x)
#define DEY   --regs.y;                \
     SETNZ(regs.y)
#define EOR   bSlowerOnPagecross = 1;                \
     regs.a ^= READ;              \
     SETNZ(regs.a)
#define HLT   regs.bJammed = 1;              \
     --regs.pc;
#define INA   ++regs.a;                \
     SETNZ(regs.a)
#define INC_NMOS bSlowerOnPagecross = 0;                \
     val = READ+1;                \
     SETNZ(val)                \
     WRITE(val)
#define INC_CMOS bSlowerOnPagecross = 1;                \
     val = READ+1;                \
     SETNZ(val)                \
     WRITE(val)
#define INS   bSlowerOnPagecross = 0;                \
     val = READ+1;                \
     WRITE(val)                \
     temp = val;                                                \
     temp2 = regs.a - temp - !flagc;          \
     if (regs.ps & AF_DECIMAL) {            \
       val  = (regs.a & 0x0F) - (temp & 0x0F) - !flagc;      \
       if (val & 0x10)              \
         val = ((val - 0x06) & 0x0F) | ((regs.a & 0xF0) - (temp & 0xF0) - 0x10);\
       else                  \
         val = (val & 0x0F) | ((regs.a & 0xF0) - (temp & 0xF0));\
       if (val & 0x100)              \
         val -= 0x60;              \
       flagc  = (temp2 < 0x100);            \
       SETNZ(temp2 & 0xFF);              \
       flagv = ((regs.a ^ temp2) & 0x80) && ((regs.a ^ temp) & 0x80);\
       regs.a = val & 0xFF;              \
     }                  \
     else {                  \
       val    = temp2;              \
       flagc  = (val < 0x100);            \
       flagv  = (((regs.a & 0x80) != (temp & 0x80)) &&      \
           ((regs.a & 0x80) != (val & 0x80)));      \
       regs.a = val & 0xFF;              \
       SETNZ(regs.a);              \
     }
#define INX   ++regs.x;                \
     SETNZ(regs.x)
#define INY   ++regs.y;                \
     SETNZ(regs.y)
#define JMP   regs.pc = addr;
#define JSR   --regs.pc;                \
     PUSH(regs.pc >> 8)              \
     PUSH(regs.pc & 0xFF)              \
     regs.pc = addr;
#define LAS   bSlowerOnPagecross = 1;                \
     val = (BYTE)(READ & regs.sp);            \
     regs.a = regs.x = (BYTE) val;            \
     regs.sp = val | 0x100;              \
     SETNZ(val)
#define LAX   bSlowerOnPagecross = 1;                \
     regs.a = regs.x = READ;            \
     SETNZ(regs.a)
#define LDA   bSlowerOnPagecross = 1;                \
     regs.a = READ;                \
     SETNZ(regs.a)
#define LDX   bSlowerOnPagecross = 1;                \
     regs.x = READ;                \
     SETNZ(regs.x)
#define LDY   bSlowerOnPagecross = 1;                \
     regs.y = READ;                \
     SETNZ(regs.y)
#define LSE   bSlowerOnPagecross = 0;                \
     val   = READ;                \
     flagc = (val & 1);              \
     val >>= 1;                \
     WRITE(val)                \
     regs.a ^= val;                \
     SETNZ(regs.a)
#define LSR_NMOS bSlowerOnPagecross = 0;                \
     val   = READ;                \
     flagc = (val & 1);              \
     flagn = 0;                \
     val >>= 1;                \
     SETZ(val)                \
     WRITE(val)
#define LSR_CMOS bSlowerOnPagecross = 1;                \
     val   = READ;                \
     flagc = (val & 1);              \
     flagn = 0;                \
     val >>= 1;                \
     SETZ(val)                \
     WRITE(val)
#define LSRA   flagc = (regs.a & 1);              \
     flagn = 0;                \
     regs.a >>= 1;                \
     SETZ(regs.a)
#define NOP   bSlowerOnPagecross = 1;
#define OAL   regs.a |= 0xEE;              \
     regs.a &= READ;              \
     regs.x = regs.a;              \
     SETNZ(regs.a)
#define ORA   bSlowerOnPagecross = 1;                \
     regs.a |= READ;              \
     SETNZ(regs.a)
#define PHA   PUSH(regs.a)
#define PHP   EF_TO_AF                \
     PUSH(regs.ps)
#define PHX   PUSH(regs.x)
#define PHY   PUSH(regs.y)
#define PLA   regs.a = POP;                \
     SETNZ(regs.a)
#define PLP   regs.ps = POP | AF_RESERVED | AF_BREAK;        \
     AF_TO_EF
#define PLX   regs.x = POP;                \
     SETNZ(regs.x)
#define PLY   regs.y = POP;                \
     SETNZ(regs.y)
#define RLA   bSlowerOnPagecross = 0;                \
     val   = (READ << 1) | flagc;            \
     flagc = (val > 0xFF);              \
     WRITE(val)                \
     regs.a &= val;                \
     SETNZ(regs.a)
#define ROL_NMOS bSlowerOnPagecross = 0;                \
     val   = (READ << 1) | flagc;            \
     flagc = (val > 0xFF);              \
     SETNZ(val)                \
     WRITE(val)
#define ROL_CMOS bSlowerOnPagecross = 1;                \
     val   = (READ << 1) | flagc;            \
     flagc = (val > 0xFF);              \
     SETNZ(val)                \
     WRITE(val)
#define ROLA   val  = (((WORD)regs.a) << 1) | flagc;        \
     flagc  = (val > 0xFF);              \
     regs.a = val & 0xFF;              \
     SETNZ(regs.a);
#define ROR_NMOS bSlowerOnPagecross = 0;                \
     temp  = READ;                \
     val   = (temp >> 1) | (flagc ? 0x80 : 0);        \
     flagc = (temp & 1);              \
     SETNZ(val)                \
     WRITE(val)
#define ROR_CMOS bSlowerOnPagecross = 1;                \
     temp  = READ;                \
     val   = (temp >> 1) | (flagc ? 0x80 : 0);        \
     flagc = (temp & 1);              \
     SETNZ(val)                \
     WRITE(val)
#define RORA   val  = (((WORD)regs.a) >> 1) | (flagc ? 0x80 : 0);      \
     flagc  = (regs.a & 1);              \
     regs.a = val & 0xFF;              \
     SETNZ(regs.a)
#define RRA   bSlowerOnPagecross = 0;                \
     temp  = READ;                \
     val   = (temp >> 1) | (flagc ? 0x80 : 0);        \
     flagc = (temp & 1);              \
     WRITE(val)                \
     temp = val;                \
     if (regs.ps & AF_DECIMAL) {            \
       val    = (regs.a & 0x0F) + (temp & 0x0F) + flagc;      \
       if (val > 0x09)              \
         val += 0x06;              \
       if (val <= 0x0F)              \
         val = (val & 0x0F) + (regs.a & 0xF0) + (temp & 0xF0);  \
       else                  \
         val = (val & 0x0F) + (regs.a & 0xF0) + (temp & 0xF0) + 0x10;\
       flagz = !((regs.a + temp + flagc) & 0xFF);        \
       flagn = (val & 0x80);            \
       flagv = ((regs.a ^ val) & 0x80) && !((regs.a ^ temp) & 0x80);\
       if ((val & 0x1F0) > 0x90)            \
         val += 0x60;              \
       flagc = ((val & 0xFF0) > 0xF0);          \
       regs.a = val & 0xFF;                                     \
     }                  \
     else {                  \
       val    = regs.a + temp + flagc;          \
       flagc  = (val > 0xFF);            \
       flagv  = (((regs.a & 0x80) == (temp & 0x80)) &&      \
           ((regs.a & 0x80) != (val & 0x80)));      \
       regs.a = val & 0xFF;              \
       SETNZ(regs.a);              \
     }
#define RTI   regs.ps = POP | AF_RESERVED | AF_BREAK;        \
     AF_TO_EF                \
     regs.pc = POP;                \
     regs.pc |= (((WORD)POP) << 8);
#define RTS   regs.pc = POP;                \
     regs.pc |= (((WORD)POP) << 8);            \
     ++regs.pc;
#define SAX   temp  = regs.a & regs.x;            \
     val  = READ;                \
     flagc  = (temp >= val);            \
     regs.x = temp-val;              \
     SETNZ(regs.x)
#define SAY   bSlowerOnPagecross = 0;                \
     val = regs.y & (((base >> 8) + 1) & 0xFF);        \
     WRITE(val)
#define SBC_NMOS bSlowerOnPagecross = 1;                \
     temp = READ;                \
     temp2 = regs.a - temp - !flagc;          \
     if (regs.ps & AF_DECIMAL) {            \
       val  = (regs.a & 0x0F) - (temp & 0x0F) - !flagc;      \
       if (val & 0x10)              \
         val = ((val - 0x06) & 0x0F) | ((regs.a & 0xF0) - (temp & 0xF0) - 0x10);\
       else                  \
         val = (val & 0x0F) | ((regs.a & 0xF0) - (temp & 0xF0));\
       if (val & 0x100)              \
         val -= 0x60;              \
       flagc  = (temp2 < 0x100);            \
       SETNZ(temp2 & 0xFF);              \
       flagv = ((regs.a ^ temp2) & 0x80) && ((regs.a ^ temp) & 0x80);\
       regs.a = val & 0xFF;              \
     }                  \
     else {                  \
       val    = temp2;              \
       flagc  = (val < 0x100);            \
       flagv  = (((regs.a & 0x80) != (temp & 0x80)) &&      \
           ((regs.a & 0x80) != (val & 0x80)));      \
       regs.a = val & 0xFF;              \
       SETNZ(regs.a);              \
     }
#define SBC_CMOS bSlowerOnPagecross = 1;                \
           temp = READ;                \
     flagv = ((regs.a ^ temp) & 0x80);          \
     if (regs.ps & AF_DECIMAL) {            \
        uExtraCycles++;              \
                    temp2 = 0x0F + (regs.a & 0x0F) - (temp & 0x0F) + flagc; \
        if (temp2 < 0x10) {              \
           val = 0;                \
           temp2 -= 0x06;              \
        }                  \
        else {                \
           val = 0x10;              \
           temp2 -= 0x10;              \
        }                  \
        val += 0xF0 + (regs.a & 0xF0) - (temp & 0xF0);      \
        if (val < 0x100) {              \
           flagc = 0;              \
           if (val < 0x80)              \
        flagv = 0;              \
           val -= 0x60;              \
        }                  \
        else {                \
           flagc = 1;              \
           if (val >= 0x180)            \
        flagv = 0;              \
        }                  \
        val += temp2;              \
     }                  \
     else {                  \
        val = 0xff + regs.a - temp + flagc;                     \
        if (val < 0x100) {              \
           flagc = 0;              \
           if (val < 0x80)              \
        flagv = 0;              \
        }                  \
        else {                \
           flagc = 1;              \
           if (val >= 0x180)            \
              flagv = 0;              \
        }                  \
     }                  \
     regs.a = val & 0xFF;              \
                 SETNZ(regs.a)
#define SEC   flagc = 1;
#define SED   regs.ps |= AF_DECIMAL;
#define SEI   regs.ps |= AF_INTERRUPT;
#define STA   bSlowerOnPagecross = 0;                \
     WRITE(regs.a)
#define STX   bSlowerOnPagecross = 0;                \
     WRITE(regs.x)
#define STY   bSlowerOnPagecross = 0;                \
     WRITE(regs.y)
#define STZ   bSlowerOnPagecross = 0;                \
     WRITE(0)
#define TAS   bSlowerOnPagecross = 0;                \
     val = regs.a & regs.x;              \
     regs.sp = 0x100 | val;              \
     val &= (((base >> 8) + 1) & 0xFF);          \
     WRITE(val)
#define TAX   regs.x = regs.a;              \
     SETNZ(regs.x)
#define TAY   regs.y = regs.a;              \
     SETNZ(regs.y)
#define TRB   bSlowerOnPagecross = 0;                \
     val   = READ;                \
     flagz = !(regs.a & val);            \
     val  &= ~regs.a;              \
     WRITE(val)
#define TSB   bSlowerOnPagecross = 0;                \
     val   = READ;                \
     flagz = !(regs.a & val);            \
     val   |= regs.a;              \
     WRITE(val)
#define TSX   regs.x = regs.sp & 0xFF;            \
     SETNZ(regs.x)
#define TXA   regs.a = regs.x;              \
     SETNZ(regs.a)
#define TXS   regs.sp = 0x100 | regs.x;
#define TYA   regs.a = regs.y;              \
     SETNZ(regs.a)
#define XAA   regs.a = regs.x;              \
     regs.a &= READ;              \
     SETNZ(regs.a)
#define XAS   bSlowerOnPagecross = 0;                \
     val = regs.x & (((base >> 8) + 1) & 0xFF);        \
     WRITE(val)

void RequestDebugger()
{
  // BUG: This causes DebugBegin to constantly be called.
  // It's as if the WM_KEYUP are auto-repeating?
  //   FrameWndProc()
  //      ProcessButtonClick()
  //         DebugBegin()
  //  PostMessage( g_hFrameWindow, WM_KEYDOWN, DEBUG_TOGGLE_KEY, 0 );
  //  PostMessage( g_hFrameWindow, WM_KEYUP  , DEBUG_TOGGLE_KEY, 0 );

  // Not a valid solution, since hitting F7 (to exit) debugger gets the debugger out of sync
  // due to EnterMessageLoop() calling ContinueExecution() after the mode has changed to DEBUG.
  //  DebugBegin();

  // Yes, we do need some sort of debugger, don't we? 0_0  --bb
//  FrameWndProc( g_hFrameWindow, WM_KEYDOWN, DEBUG_TOGGLE_KEY, 0 );
//  FrameWndProc( g_hFrameWindow, WM_KEYUP  , DEBUG_TOGGLE_KEY, 0 );
}

bool CheckDebugBreak( int iOpcode )
{
  if (g_bDebugDelayBreakCheck)
  {
    g_bDebugDelayBreakCheck = false;
    return false;
  }

  // Running at full speed? (debugger not running)
  if ((g_nAppMode != MODE_DEBUG) && (g_nAppMode != MODE_STEPPING))
  {
    if (((iOpcode == 0) && IsDebugBreakOnInvalid(0)) ||
      ((g_iDebugOnOpcode) && (g_iDebugOnOpcode == iOpcode))) // User wants to enter debugger on opcode?
    {
      RequestDebugger();
      return true;
    }
  }

  return false;
}

// Break into debugger on invalid opcodes
#define INV if (IsDebugBreakOnInvalid(1)) { RequestDebugger(); bBreakOnInvalid = true; }

/****************************************************************************
*
*  OPCODE TABLE
*
***/

unsigned __int64 g_nCycleIrqStart;
unsigned __int64 g_nCycleIrqEnd;
UINT g_nCycleIrqTime;

UINT g_nIdx = 0;
const UINT BUFFER_SIZE = 4096;  // 80 secs
UINT g_nBuffer[BUFFER_SIZE];
UINT g_nMean = 0;
UINT g_nMin = 0xFFFFFFFF;
UINT g_nMax = 0;

static inline void DoIrqProfiling(DWORD uCycles)
{
#ifdef _DEBUG
  if(regs.ps & AF_INTERRUPT)
    return;    // Still in Apple's ROM

  g_nCycleIrqEnd = g_nCumulativeCycles + uCycles;
  g_nCycleIrqTime = (UINT) (g_nCycleIrqEnd - g_nCycleIrqStart);

  if(g_nCycleIrqTime > g_nMax) g_nMax = g_nCycleIrqTime;
  if(g_nCycleIrqTime < g_nMin) g_nMin = g_nCycleIrqTime;

  if(g_nIdx == BUFFER_SIZE)
    return;

  g_nBuffer[g_nIdx] = g_nCycleIrqTime;
  g_nIdx++;

  if(g_nIdx == BUFFER_SIZE)
  {
    UINT nTotal = 0;
    for(UINT i=0; i<BUFFER_SIZE; i++)
      nTotal += g_nBuffer[i];

    g_nMean = nTotal / BUFFER_SIZE;
  }
#endif
}

//===========================================================================

static inline int Fetch(BYTE& iOpcode, ULONG uExecutedCycles)
{
    g_uInternalExecutedCycles = uExecutedCycles;

//    iOpcode = *(mem+regs.pc);
    iOpcode = ((regs.pc & 0xF000) == 0xC000)
        ? IORead[(regs.pc>>4) & 0xFF](regs.pc,regs.pc,0,0,uExecutedCycles)  // Fetch opcode from I/O memory, but params are still from mem[]
      : *(mem+regs.pc);

    if (CheckDebugBreak( iOpcode ))
      return 0;

    regs.pc++;
    return 1;
}

//#define ENABLE_NMI_SUPPORT  // Not used - so don't enable
static inline void NMI(ULONG& uExecutedCycles, UINT& uExtraCycles, BOOL& flagc, BOOL& flagn, BOOL& flagv, BOOL& flagz)
{
#ifdef ENABLE_NMI_SUPPORT
  if(g_bNmiFlank)
  {
    // NMI signals are only serviced once
    g_bNmiFlank = FALSE;
    g_nCycleIrqStart = g_nCumulativeCycles + uExecutedCycles;
    PUSH(regs.pc >> 8)
    PUSH(regs.pc & 0xFF)
    EF_TO_AF
    PUSH(regs.ps & ~AF_BREAK)
    regs.ps = regs.ps | AF_INTERRUPT & ~AF_DECIMAL;
    regs.pc = * (WORD*) (mem+0xFFFA);
    CYC(7)
  }
#endif
}

static inline void IRQ(ULONG& uExecutedCycles, UINT& uExtraCycles, BOOL& flagc, BOOL& flagn, BOOL& flagv, BOOL& flagz)
{
  if(g_bmIRQ && !(regs.ps & AF_INTERRUPT))
  {
    // IRQ signals are deasserted when a specific r/w operation is done on device
    g_nCycleIrqStart = g_nCumulativeCycles + uExecutedCycles;
    PUSH(regs.pc >> 8)
    PUSH(regs.pc & 0xFF)
    EF_TO_AF
    PUSH(regs.ps & ~AF_BREAK)
    regs.ps = (regs.ps | AF_INTERRUPT) & (~AF_DECIMAL);
    regs.pc = * (WORD*) (mem+0xFFFE);
    CYC(7)
  }
}

static inline void CheckInterruptSources(ULONG uExecutedCycles)
{
  if (g_nIrqCheckTimeout < 0)
  {
#ifndef UPDATE_ALL_PER_CYCLE
    MB_UpdateCycles(uExecutedCycles);
#endif
    sg_Mouse.SetVBlank(VideoGetVbl(uExecutedCycles));
    g_nIrqCheckTimeout = IRQ_CHECK_TIMEOUT;
  }
}

//===========================================================================

static DWORD Cpu65C02 (DWORD uTotalCycles)
{
  // Optimisation:
  // . Copy the global /regs/ vars to stack-based local vars
  //   (Oliver Schmidt says this gives a performance gain, see email - The real deal: "1.10.5")
  WORD addr;
  BOOL flagc; // must always be 0 or 1, no other values allowed
  BOOL flagn; // must always be 0 or 0x80.
  BOOL flagv; // any value allowed
  BOOL flagz; // any value allowed
  WORD temp;
  WORD temp2;
  WORD val;
  AF_TO_EF
  ULONG uExecutedCycles = 0;
  BOOL bSlowerOnPagecross;    // Set if opcode writes to memory (eg. ASL, STA)
  WORD base;
  bool bBreakOnInvalid = false;

  do
  {
    UINT uExtraCycles = 0;
    BYTE iOpcode;

    if (!Fetch(iOpcode, uExecutedCycles))
      break;

    switch (iOpcode)
    {
    case 0x00:       BRK       CYC(7)  break;
    case 0x01:       INDX ORA       CYC(6)  break;
    case 0x02:   INV IMM NOP       CYC(2)  break;
    case 0x03:   INV NOP       CYC(2)  break;
    case 0x04:       ZPG TSB       CYC(5)  break;
    case 0x05:       ZPG ORA       CYC(3)  break;
    case 0x06:       ZPG ASL_CMOS  CYC(5)  break;
    case 0x07:   INV NOP       CYC(2)  break;
    case 0x08:       PHP       CYC(3)  break;
    case 0x09:       IMM ORA       CYC(2)  break;
    case 0x0A:       ASLA       CYC(2)  break;
    case 0x0B:   INV NOP       CYC(2)  break;
    case 0x0C:       ABS TSB       CYC(6)  break;
    case 0x0D:       ABS ORA       CYC(4)  break;
    case 0x0E:       ABS ASL_CMOS  CYC(6)  break;
    case 0x0F:   INV NOP       CYC(2)  break;
    case 0x10:       REL BPL       CYC(2)  break;
    case 0x11:       INDY ORA       CYC(5)  break;
    case 0x12:       IZPG ORA       CYC(5)  break;
    case 0x13:   INV NOP       CYC(2)  break;
    case 0x14:       ZPG TRB       CYC(5)  break;
    case 0x15:       ZPGX ORA       CYC(4)  break;
    case 0x16:       ZPGX ASL_CMOS CYC(6)  break;
    case 0x17:   INV NOP       CYC(2)  break;
    case 0x18:       CLC       CYC(2)  break;
    case 0x19:       ABSY ORA       CYC(4)  break;
    case 0x1A:       INA       CYC(2)  break;
    case 0x1B:   INV NOP       CYC(2)  break;
    case 0x1C:       ABS TRB       CYC(6)  break;
    case 0x1D:       ABSX ORA       CYC(4)  break;
    case 0x1E:       ABSX ASL_CMOS CYC(6)  break;
    case 0x1F:   INV NOP       CYC(2)  break;
    case 0x20:       ABS JSR       CYC(6)  break;
    case 0x21:       INDX AND       CYC(6)  break;
    case 0x22:   INV IMM NOP       CYC(2)  break;
    case 0x23:   INV NOP       CYC(2)  break;
    case 0x24:       ZPG BIT       CYC(3)  break;
    case 0x25:       ZPG AND       CYC(3)  break;
    case 0x26:       ZPG ROL_CMOS  CYC(5)  break;
    case 0x27:   INV NOP       CYC(2)  break;
    case 0x28:       PLP       CYC(4)  break;
    case 0x29:       IMM AND       CYC(2)  break;
    case 0x2A:       ROLA       CYC(2)  break;
    case 0x2B:   INV NOP       CYC(2)  break;
    case 0x2C:       ABS BIT       CYC(4)  break;
    case 0x2D:       ABS AND       CYC(2)  break;
    case 0x2E:       ABS ROL_CMOS  CYC(6)  break;
    case 0x2F:   INV NOP       CYC(2)  break;
    case 0x30:       REL BMI       CYC(2)  break;
    case 0x31:       INDY AND       CYC(5)  break;
    case 0x32:       IZPG AND       CYC(5)  break;
    case 0x33:   INV NOP       CYC(2)  break;
    case 0x34:       ZPGX BIT       CYC(4)  break;
    case 0x35:       ZPGX AND       CYC(4)  break;
    case 0x36:       ZPGX ROL_CMOS CYC(6)  break;
    case 0x37:   INV NOP       CYC(2)  break;
    case 0x38:       SEC       CYC(2)  break;
    case 0x39:       ABSY AND       CYC(4)  break;
    case 0x3A:       DEA       CYC(2)  break;
    case 0x3B:   INV NOP       CYC(2)  break;
    case 0x3C:       ABSX BIT       CYC(4)  break;
    case 0x3D:       ABSX AND       CYC(4)  break;
    case 0x3E:       ABSX ROL_CMOS CYC(6)  break;
    case 0x3F:   INV NOP       CYC(2)  break;
    case 0x40:       RTI       CYC(6)  DoIrqProfiling(uExecutedCycles); break;
    case 0x41:       INDX EOR       CYC(6)  break;
    case 0x42:   INV IMM NOP       CYC(2)  break;
    case 0x43:   INV NOP       CYC(2)  break;
    case 0x44:   INV ZPG NOP       CYC(3)  break;
    case 0x45:       ZPG EOR       CYC(3)  break;
    case 0x46:       ZPG LSR_CMOS  CYC(5)  break;
    case 0x47:   INV NOP       CYC(2)  break;
    case 0x48:       PHA       CYC(3)  break;
    case 0x49:       IMM EOR       CYC(2)  break;
    case 0x4A:       LSRA       CYC(2)  break;
    case 0x4B:   INV NOP       CYC(2)  break;
    case 0x4C:       ABS JMP       CYC(3)  break;
    case 0x4D:       ABS EOR       CYC(4)  break;
    case 0x4E:       ABS LSR_CMOS  CYC(6)  break;
    case 0x4F:   INV NOP       CYC(2)  break;
    case 0x50:       REL BVC       CYC(2)  break;
    case 0x51:       INDY EOR       CYC(5)  break;
    case 0x52:       IZPG EOR       CYC(5)  break;
    case 0x53:   INV NOP       CYC(2)  break;
    case 0x54:   INV ZPGX NOP       CYC(4)  break;
    case 0x55:       ZPGX EOR       CYC(4)  break;
    case 0x56:       ZPGX LSR_CMOS CYC(6)  break;
    case 0x57:   INV NOP       CYC(2)  break;
    case 0x58:       CLI       CYC(2)  break;
    case 0x59:       ABSY EOR       CYC(4)  break;
    case 0x5A:       PHY       CYC(3)  break;
    case 0x5B:   INV NOP       CYC(2)  break;
    case 0x5C:   INV ABSX NOP       CYC(8)  break;
    case 0x5D:       ABSX EOR       CYC(4)  break;
    case 0x5E:       ABSX LSR_CMOS CYC(6)  break;
    case 0x5F:   INV NOP       CYC(2)  break;
    case 0x60:       RTS       CYC(6)  break;
    case 0x61:       INDX ADC_CMOS CYC(6)  break;
    case 0x62:   INV IMM NOP       CYC(2)  break;
    case 0x63:   INV NOP       CYC(2)  break;
    case 0x64:       ZPG STZ       CYC(3)  break;
    case 0x65:       ZPG ADC_CMOS  CYC(3)  break;
    case 0x66:       ZPG ROR_CMOS  CYC(5)  break;
    case 0x67:   INV NOP       CYC(2)  break;
    case 0x68:       PLA       CYC(4)  break;
    case 0x69:       IMM ADC_CMOS  CYC(2)  break;
    case 0x6A:       RORA       CYC(2)  break;
    case 0x6B:   INV NOP       CYC(2)  break;
    case 0x6C:       IABSCMOS JMP  CYC(6)  break;
    case 0x6D:       ABS ADC_CMOS  CYC(4)  break;
    case 0x6E:       ABS ROR_CMOS  CYC(6)  break;
    case 0x6F:   INV NOP       CYC(2)  break;
    case 0x70:       REL BVS       CYC(2)  break;
    case 0x71:       INDY ADC_CMOS CYC(5)  break;
    case 0x72:       IZPG ADC_CMOS CYC(5)  break;
    case 0x73:   INV NOP       CYC(2)  break;
    case 0x74:       ZPGX STZ       CYC(4)  break;
    case 0x75:       ZPGX ADC_CMOS CYC(4)  break;
    case 0x76:       ZPGX ROR_CMOS CYC(6)  break;
    case 0x77:   INV NOP       CYC(2)  break;
    case 0x78:       SEI       CYC(2)  break;
    case 0x79:       ABSY ADC_CMOS CYC(4)  break;
    case 0x7A:       PLY       CYC(4)  break;
    case 0x7B:   INV NOP       CYC(2)  break;
    case 0x7C:       IABSX JMP     CYC(6)  break;
    case 0x7D:       ABSX ADC_CMOS CYC(4)  break;
    case 0x7E:       ABSX ROR_CMOS CYC(6)  break;
    case 0x7F:   INV NOP       CYC(2)  break;
    case 0x80:       REL BRA       CYC(2)  break;
    case 0x81:       INDX STA       CYC(6)  break;
    case 0x82:   INV IMM NOP       CYC(2)  break;
    case 0x83:   INV NOP       CYC(2)  break;
    case 0x84:       ZPG STY       CYC(3)  break;
    case 0x85:       ZPG STA       CYC(3)  break;
    case 0x86:       ZPG STX       CYC(3)  break;
    case 0x87:   INV NOP       CYC(2)  break;
    case 0x88:       DEY       CYC(2)  break;
    case 0x89:       IMM BITI       CYC(2)  break;
    case 0x8A:       TXA       CYC(2)  break;
    case 0x8B:   INV NOP       CYC(2)  break;
    case 0x8C:       ABS STY       CYC(4)  break;
    case 0x8D:       ABS STA       CYC(4)  break;
    case 0x8E:       ABS STX       CYC(4)  break;
    case 0x8F:   INV NOP       CYC(2)  break;
    case 0x90:       REL BCC       CYC(2)  break;
    case 0x91:       INDY STA       CYC(6)  break;
    case 0x92:       IZPG STA       CYC(5)  break;
    case 0x93:   INV NOP       CYC(2)  break;
    case 0x94:       ZPGX STY       CYC(4)  break;
    case 0x95:       ZPGX STA       CYC(4)  break;
    case 0x96:       ZPGY STX       CYC(4)  break;
    case 0x97:   INV NOP       CYC(2)  break;
    case 0x98:       TYA       CYC(2)  break;
    case 0x99:       ABSY STA       CYC(5)  break;
    case 0x9A:       TXS       CYC(2)  break;
    case 0x9B:   INV NOP       CYC(2)  break;
    case 0x9C:       ABS STZ       CYC(4)  break;
    case 0x9D:       ABSX STA       CYC(5)  break;
    case 0x9E:       ABSX STZ       CYC(5)  break;
    case 0x9F:   INV NOP       CYC(2)  break;
    case 0xA0:       IMM LDY       CYC(2)  break;
    case 0xA1:       INDX LDA       CYC(6)  break;
    case 0xA2:       IMM LDX       CYC(2)  break;
    case 0xA3:   INV NOP       CYC(2)  break;
    case 0xA4:       ZPG LDY       CYC(3)  break;
    case 0xA5:       ZPG LDA       CYC(3)  break;
    case 0xA6:       ZPG LDX       CYC(3)  break;
    case 0xA7:   INV NOP       CYC(2)  break;
    case 0xA8:       TAY       CYC(2)  break;
    case 0xA9:       IMM LDA       CYC(2)  break;
    case 0xAA:       TAX       CYC(2)  break;
    case 0xAB:   INV NOP       CYC(2)  break;
    case 0xAC:       ABS LDY       CYC(4)  break;
    case 0xAD:       ABS LDA       CYC(4)  break;
    case 0xAE:       ABS LDX       CYC(4)  break;
    case 0xAF:   INV NOP       CYC(2)  break;
    case 0xB0:       REL BCS       CYC(2)  break;
    case 0xB1:       INDY LDA       CYC(5)  break;
    case 0xB2:       IZPG LDA       CYC(5)  break;
    case 0xB3:   INV NOP       CYC(2)  break;
    case 0xB4:       ZPGX LDY       CYC(4)  break;
    case 0xB5:       ZPGX LDA       CYC(4)  break;
    case 0xB6:       ZPGY LDX       CYC(4)  break;
    case 0xB7:   INV NOP       CYC(2)  break;
    case 0xB8:       CLV       CYC(2)  break;
    case 0xB9:       ABSY LDA       CYC(4)  break;
    case 0xBA:       TSX       CYC(2)  break;
    case 0xBB:   INV NOP       CYC(2)  break;
    case 0xBC:       ABSX LDY       CYC(4)  break;
    case 0xBD:       ABSX LDA       CYC(4)  break;
    case 0xBE:       ABSY LDX       CYC(4)  break;
    case 0xBF:   INV NOP       CYC(2)  break;
    case 0xC0:       IMM CPY       CYC(2)  break;
    case 0xC1:       INDX CMP       CYC(6)  break;
    case 0xC2:   INV IMM NOP       CYC(2)  break;
    case 0xC3:   INV NOP       CYC(2)  break;
    case 0xC4:       ZPG CPY       CYC(3)  break;
    case 0xC5:       ZPG CMP       CYC(3)  break;
    case 0xC6:       ZPG DEC_CMOS  CYC(5)  break;
    case 0xC7:   INV NOP       CYC(2)  break;
    case 0xC8:       INY       CYC(2)  break;
    case 0xC9:       IMM CMP       CYC(2)  break;
    case 0xCA:       DEX       CYC(2)  break;
    case 0xCB:   INV NOP       CYC(2)  break;
    case 0xCC:       ABS CPY       CYC(4)  break;
    case 0xCD:       ABS CMP       CYC(4)  break;
    case 0xCE:       ABS DEC_CMOS  CYC(5)  break;
    case 0xCF:   INV NOP       CYC(2)  break;
    case 0xD0:       REL BNE       CYC(2)  break;
    case 0xD1:       INDY CMP       CYC(5)  break;
    case 0xD2:       IZPG CMP       CYC(5)  break;
    case 0xD3:   INV NOP       CYC(2)  break;
    case 0xD4:   INV ZPGX NOP       CYC(4)  break;
    case 0xD5:       ZPGX CMP       CYC(4)  break;
    case 0xD6:       ZPGX DEC_CMOS CYC(6)  break;
    case 0xD7:   INV NOP       CYC(2)  break;
    case 0xD8:       CLD       CYC(2)  break;
    case 0xD9:       ABSY CMP       CYC(4)  break;
    case 0xDA:       PHX       CYC(3)  break;
    case 0xDB:   INV NOP       CYC(2)  break;
    case 0xDC:   INV ABSX NOP       CYC(4)  break;
    case 0xDD:       ABSX CMP       CYC(4)  break;
    case 0xDE:       ABSX DEC_CMOS CYC(6)  break;
    case 0xDF:   INV NOP       CYC(2)  break;
    case 0xE0:       IMM CPX       CYC(2)  break;
    case 0xE1:       INDX SBC_CMOS CYC(6)  break;
    case 0xE2:   INV IMM NOP       CYC(2)  break;
    case 0xE3:   INV NOP       CYC(2)  break;
    case 0xE4:       ZPG CPX       CYC(3)  break;
    case 0xE5:       ZPG SBC_CMOS  CYC(3)  break;
    case 0xE6:       ZPG INC_CMOS  CYC(5)  break;
    case 0xE7:   INV NOP       CYC(2)  break;
    case 0xE8:       INX       CYC(2)  break;
    case 0xE9:       IMM SBC_CMOS  CYC(2)  break;
    case 0xEA:       NOP       CYC(2)  break;
    case 0xEB:   INV NOP       CYC(2)  break;
    case 0xEC:       ABS CPX       CYC(4)  break;
    case 0xED:       ABS SBC_CMOS  CYC(4)  break;
    case 0xEE:       ABS INC_CMOS  CYC(6)  break;
    case 0xEF:   INV NOP       CYC(2)  break;
    case 0xF0:       REL BEQ       CYC(2)  break;
    case 0xF1:       INDY SBC_CMOS CYC(5)  break;
    case 0xF2:       IZPG SBC_CMOS CYC(5)  break;
    case 0xF3:   INV NOP       CYC(2)  break;
    case 0xF4:   INV ZPGX NOP       CYC(4)  break;
    case 0xF5:       ZPGX SBC_CMOS CYC(4)  break;
    case 0xF6:       ZPGX INC_CMOS CYC(6)  break;
    case 0xF7:   INV NOP       CYC(2)  break;
    case 0xF8:       SED       CYC(2)  break;
    case 0xF9:       ABSY SBC_CMOS CYC(4)  break;
    case 0xFA:       PLX       CYC(4)  break;
    case 0xFB:   INV NOP       CYC(2)  break;
    case 0xFC:   INV ABSX NOP       CYC(4)  break;
    case 0xFD:       ABSX SBC_CMOS CYC(4)  break;
    case 0xFE:       ABSX INC_CMOS CYC(6)  break;
    case 0xFF:   INV NOP       CYC(2)  break;
    }


    CheckInterruptSources(uExecutedCycles);
    NMI(uExecutedCycles, uExtraCycles, flagc, flagn, flagv, flagz);
    IRQ(uExecutedCycles, uExtraCycles, flagc, flagn, flagv, flagz);

    if (bBreakOnInvalid) // break to debugger window?
      break;

  } while (uExecutedCycles < uTotalCycles);

  EF_TO_AF
  return uExecutedCycles;
}

//===========================================================================

static DWORD Cpu6502 (DWORD uTotalCycles)
{
  WORD addr;
  BOOL flagc; // must always be 0 or 1, no other values allowed
  BOOL flagn; // must always be 0 or 0x80.
  BOOL flagv; // any value allowed
  BOOL flagz; // any value allowed
  WORD temp;
  WORD temp2;
  WORD val;
  AF_TO_EF
  ULONG uExecutedCycles = 0;
  BOOL bSlowerOnPagecross;    // Set if opcode writes to memory (eg. ASL, STA)
  WORD base;
  bool bBreakOnInvalid = false;

  do
  {
    UINT uExtraCycles = 0;
    BYTE iOpcode;

    if (!Fetch(iOpcode, uExecutedCycles))
      break;

    switch (iOpcode)
    {
    case 0x00:       BRK       CYC(7)  break;
    case 0x01:       INDX ORA       CYC(6)  break;
    case 0x02:   INV HLT       CYC(2)  break;
    case 0x03:   INV INDX ASO       CYC(8)  break;
    case 0x04:   INV ZPG NOP       CYC(3)  break;
    case 0x05:       ZPG ORA       CYC(3)  break;
    case 0x06:       ZPG ASL_NMOS  CYC(5)  break;
    case 0x07:   INV ZPG ASO       CYC(5)  break;
    case 0x08:       PHP       CYC(3)  break;
    case 0x09:       IMM ORA       CYC(2)  break;
    case 0x0A:       ASLA       CYC(2)  break;
    case 0x0B:   INV IMM ANC       CYC(2)  break;
    case 0x0C:   INV ABSX NOP       CYC(4)  break;
    case 0x0D:       ABS ORA       CYC(4)  break;
    case 0x0E:       ABS ASL_NMOS  CYC(6)  break;
    case 0x0F:   INV ABS ASO       CYC(6)  break;
    case 0x10:       REL BPL       CYC(2)  break;
    case 0x11:       INDY ORA       CYC(5)  break;
    case 0x12:   INV HLT       CYC(2)  break;
    case 0x13:   INV INDY ASO       CYC(8)  break;
    case 0x14:   INV ZPGX NOP       CYC(4)  break;
    case 0x15:       ZPGX ORA       CYC(4)  break;
    case 0x16:       ZPGX ASL_NMOS CYC(6)  break;
    case 0x17:   INV ZPGX ASO       CYC(6)  break;
    case 0x18:       CLC       CYC(2)  break;
    case 0x19:       ABSY ORA       CYC(4)  break;
    case 0x1A:   INV NOP       CYC(2)  break;
    case 0x1B:   INV ABSY ASO       CYC(7)  break;
    case 0x1C:   INV ABSX NOP       CYC(4)  break;
    case 0x1D:       ABSX ORA       CYC(4)  break;
    case 0x1E:       ABSX ASL_NMOS CYC(6)  break;
    case 0x1F:   INV ABSX ASO       CYC(7)  break;
    case 0x20:       ABS JSR       CYC(6)  break;
    case 0x21:       INDX AND       CYC(6)  break;
    case 0x22:   INV HLT       CYC(2)  break;
    case 0x23:   INV INDX RLA       CYC(8)  break;
    case 0x24:       ZPG BIT       CYC(3)  break;
    case 0x25:       ZPG AND       CYC(3)  break;
    case 0x26:       ZPG ROL_NMOS  CYC(5)  break;
    case 0x27:   INV ZPG RLA       CYC(5)  break;
    case 0x28:       PLP       CYC(4)  break;
    case 0x29:       IMM AND       CYC(2)  break;
    case 0x2A:       ROLA       CYC(2)  break;
    case 0x2B:   INV IMM ANC       CYC(2)  break;
    case 0x2C:       ABS BIT       CYC(4)  break;
    case 0x2D:       ABS AND       CYC(2)  break;
    case 0x2E:       ABS ROL_NMOS  CYC(6)  break;
    case 0x2F:   INV ABS RLA       CYC(6)  break;
    case 0x30:       REL BMI       CYC(2)  break;
    case 0x31:       INDY AND       CYC(5)  break;
    case 0x32:   INV HLT       CYC(2)  break;
    case 0x33:   INV INDY RLA       CYC(8)  break;
    case 0x34:   INV ZPGX NOP       CYC(4)  break;
    case 0x35:       ZPGX AND       CYC(4)  break;
    case 0x36:       ZPGX ROL_NMOS CYC(6)  break;
    case 0x37:   INV ZPGX RLA       CYC(6)  break;
    case 0x38:       SEC       CYC(2)  break;
    case 0x39:       ABSY AND       CYC(4)  break;
    case 0x3A:   INV NOP       CYC(2)  break;
    case 0x3B:   INV ABSY RLA       CYC(7)  break;
    case 0x3C:   INV ABSX NOP       CYC(4)  break;
    case 0x3D:       ABSX AND       CYC(4)  break;
    case 0x3E:       ABSX ROL_NMOS CYC(6)  break;
    case 0x3F:   INV ABSX RLA       CYC(7)  break;
    case 0x40:       RTI       CYC(6)  DoIrqProfiling(uExecutedCycles); break;
    case 0x41:       INDX EOR       CYC(6)  break;
    case 0x42:   INV HLT       CYC(2)  break;
    case 0x43:   INV INDX LSE       CYC(8)  break;
    case 0x44:   INV ZPG NOP       CYC(3)  break;
    case 0x45:       ZPG EOR       CYC(3)  break;
    case 0x46:       ZPG LSR_NMOS  CYC(5)  break;
    case 0x47:   INV ZPG LSE       CYC(5)  break;
    case 0x48:       PHA       CYC(3)  break;
    case 0x49:       IMM EOR       CYC(2)  break;
    case 0x4A:       LSRA       CYC(2)  break;
    case 0x4B:   INV IMM ALR       CYC(2)  break;
    case 0x4C:       ABS JMP       CYC(3)  break;
    case 0x4D:       ABS EOR       CYC(4)  break;
    case 0x4E:       ABS LSR_NMOS  CYC(6)  break;
    case 0x4F:   INV ABS LSE       CYC(6)  break;
    case 0x50:       REL BVC       CYC(2)  break;
    case 0x51:       INDY EOR       CYC(5)  break;
    case 0x52:   INV HLT       CYC(2)  break;
    case 0x53:   INV INDY LSE       CYC(8)  break;
    case 0x54:   INV ZPGX NOP       CYC(4)  break;
    case 0x55:       ZPGX EOR       CYC(4)  break;
    case 0x56:       ZPGX LSR_NMOS CYC(6)  break;
    case 0x57:   INV ZPGX LSE       CYC(6)  break;
    case 0x58:       CLI       CYC(2)  break;
    case 0x59:       ABSY EOR       CYC(4)  break;
    case 0x5A:   INV NOP       CYC(2)  break;
    case 0x5B:   INV ABSY LSE       CYC(7)  break;
    case 0x5C:   INV ABSX NOP       CYC(4)  break;
    case 0x5D:       ABSX EOR       CYC(4)  break;
    case 0x5E:       ABSX LSR_NMOS CYC(6)  break;
    case 0x5F:   INV ABSX LSE       CYC(7)  break;
    case 0x60:       RTS       CYC(6)  break;
    case 0x61:       INDX ADC_NMOS CYC(6)  break;
    case 0x62:   INV HLT       CYC(2)  break;
    case 0x63:   INV INDX RRA       CYC(8)  break;
    case 0x64:   INV ZPG NOP       CYC(3)  break;
    case 0x65:       ZPG ADC_NMOS  CYC(3)  break;
    case 0x66:       ZPG ROR_NMOS  CYC(5)  break;
    case 0x67:   INV ZPG RRA       CYC(5)  break;
    case 0x68:       PLA       CYC(4)  break;
    case 0x69:       IMM ADC_NMOS  CYC(2)  break;
    case 0x6A:       RORA       CYC(2)  break;
    case 0x6B:   INV IMM ARR       CYC(2)  break;
    case 0x6C:       IABSNMOS JMP  CYC(6)  break;
    case 0x6D:       ABS ADC_NMOS  CYC(4)  break;
    case 0x6E:       ABS ROR_NMOS  CYC(6)  break;
    case 0x6F:   INV ABS RRA       CYC(6)  break;
    case 0x70:       REL BVS       CYC(2)  break;
    case 0x71:       INDY ADC_NMOS CYC(5)  break;
    case 0x72:   INV HLT       CYC(2)  break;
    case 0x73:   INV INDY RRA       CYC(8)  break;
    case 0x74:   INV ZPGX NOP       CYC(4)  break;
    case 0x75:       ZPGX ADC_NMOS CYC(4)  break;
    case 0x76:       ZPGX ROR_NMOS CYC(6)  break;
    case 0x77:   INV ZPGX RRA       CYC(6)  break;
    case 0x78:       SEI       CYC(2)  break;
    case 0x79:       ABSY ADC_NMOS CYC(4)  break;
    case 0x7A:   INV NOP       CYC(2)  break;
    case 0x7B:   INV ABSY RRA       CYC(7)  break;
    case 0x7C:   INV ABSX NOP       CYC(4)  break;
    case 0x7D:       ABSX ADC_NMOS CYC(4)  break;
    case 0x7E:       ABSX ROR_NMOS CYC(6)  break;
    case 0x7F:   INV ABSX RRA       CYC(7)  break;
    case 0x80:   INV IMM NOP       CYC(2)  break;
    case 0x81:       INDX STA       CYC(6)  break;
    case 0x82:   INV IMM NOP       CYC(2)  break;
    case 0x83:   INV INDX AXS       CYC(6)  break;
    case 0x84:       ZPG STY       CYC(3)  break;
    case 0x85:       ZPG STA       CYC(3)  break;
    case 0x86:       ZPG STX       CYC(3)  break;
    case 0x87:   INV ZPG AXS       CYC(3)  break;
    case 0x88:       DEY       CYC(2)  break;
    case 0x89:   INV IMM NOP       CYC(2)  break;
    case 0x8A:       TXA       CYC(2)  break;
    case 0x8B:   INV IMM XAA       CYC(2)  break;
    case 0x8C:       ABS STY       CYC(4)  break;
    case 0x8D:       ABS STA       CYC(4)  break;
    case 0x8E:       ABS STX       CYC(4)  break;
    case 0x8F:   INV ABS AXS       CYC(4)  break;
    case 0x90:       REL BCC       CYC(2)  break;
    case 0x91:       INDY STA       CYC(6)  break;
    case 0x92:   INV HLT       CYC(2)  break;
    case 0x93:   INV INDY AXA       CYC(6)  break;
    case 0x94:       ZPGX STY       CYC(4)  break;
    case 0x95:       ZPGX STA       CYC(4)  break;
    case 0x96:       ZPGY STX       CYC(4)  break;
    case 0x97:   INV ZPGY AXS       CYC(4)  break;
    case 0x98:       TYA       CYC(2)  break;
    case 0x99:       ABSY STA       CYC(5)  break;
    case 0x9A:       TXS       CYC(2)  break;
    case 0x9B:   INV ABSY TAS       CYC(5)  break;
    case 0x9C:   INV ABSX SAY       CYC(5)  break;
    case 0x9D:       ABSX STA       CYC(5)  break;
    case 0x9E:   INV ABSY XAS       CYC(5)  break;
    case 0x9F:   INV ABSY AXA       CYC(5)  break;
    case 0xA0:       IMM LDY       CYC(2)  break;
    case 0xA1:       INDX LDA       CYC(6)  break;
    case 0xA2:       IMM LDX       CYC(2)  break;
    case 0xA3:   INV INDX LAX       CYC(6)  break;
    case 0xA4:       ZPG LDY       CYC(3)  break;
    case 0xA5:       ZPG LDA       CYC(3)  break;
    case 0xA6:       ZPG LDX       CYC(3)  break;
    case 0xA7:   INV ZPG LAX       CYC(3)  break;
    case 0xA8:       TAY       CYC(2)  break;
    case 0xA9:       IMM LDA       CYC(2)  break;
    case 0xAA:       TAX       CYC(2)  break;
    case 0xAB:   INV IMM OAL       CYC(2)  break;
    case 0xAC:       ABS LDY       CYC(4)  break;
    case 0xAD:       ABS LDA       CYC(4)  break;
    case 0xAE:       ABS LDX       CYC(4)  break;
    case 0xAF:   INV ABS LAX       CYC(4)  break;
    case 0xB0:       REL BCS       CYC(2)  break;
    case 0xB1:       INDY LDA       CYC(5)  break;
    case 0xB2:   INV HLT       CYC(2)  break;
    case 0xB3:   INV INDY LAX       CYC(5)  break;
    case 0xB4:       ZPGX LDY       CYC(4)  break;
    case 0xB5:       ZPGX LDA       CYC(4)  break;
    case 0xB6:       ZPGY LDX       CYC(4)  break;
    case 0xB7:   INV ZPGY LAX       CYC(4)  break;
    case 0xB8:       CLV       CYC(2)  break;
    case 0xB9:       ABSY LDA       CYC(4)  break;
    case 0xBA:       TSX       CYC(2)  break;
    case 0xBB:   INV ABSY LAS       CYC(4)  break;
    case 0xBC:       ABSX LDY       CYC(4)  break;
    case 0xBD:       ABSX LDA       CYC(4)  break;
    case 0xBE:       ABSY LDX       CYC(4)  break;
    case 0xBF:   INV ABSY LAX       CYC(4)  break;
    case 0xC0:       IMM CPY       CYC(2)  break;
    case 0xC1:       INDX CMP       CYC(6)  break;
    case 0xC2:   INV IMM NOP       CYC(2)  break;
    case 0xC3:   INV INDX DCM       CYC(8)  break;
    case 0xC4:       ZPG CPY       CYC(3)  break;
    case 0xC5:       ZPG CMP       CYC(3)  break;
    case 0xC6:       ZPG DEC_NMOS  CYC(5)  break;
    case 0xC7:   INV ZPG DCM       CYC(5)  break;
    case 0xC8:       INY       CYC(2)  break;
    case 0xC9:       IMM CMP       CYC(2)  break;
    case 0xCA:       DEX       CYC(2)  break;
    case 0xCB:   INV IMM SAX       CYC(2)  break;
    case 0xCC:       ABS CPY       CYC(4)  break;
    case 0xCD:       ABS CMP       CYC(4)  break;
    case 0xCE:       ABS DEC_NMOS  CYC(5)  break;
    case 0xCF:   INV ABS DCM       CYC(6)  break;
    case 0xD0:       REL BNE       CYC(2)  break;
    case 0xD1:       INDY CMP       CYC(5)  break;
    case 0xD2:   INV HLT       CYC(2)  break;
    case 0xD3:   INV INDY DCM       CYC(8)  break;
    case 0xD4:   INV ZPGX NOP       CYC(4)  break;
    case 0xD5:       ZPGX CMP       CYC(4)  break;
    case 0xD6:       ZPGX DEC_NMOS CYC(6)  break;
    case 0xD7:   INV ZPGX DCM       CYC(6)  break;
    case 0xD8:       CLD       CYC(2)  break;
    case 0xD9:       ABSY CMP       CYC(4)  break;
    case 0xDA:   INV NOP       CYC(2)  break;
    case 0xDB:   INV ABSY DCM       CYC(7)  break;
    case 0xDC:   INV ABSX NOP       CYC(4)  break;
    case 0xDD:       ABSX CMP       CYC(4)  break;
    case 0xDE:       ABSX DEC_NMOS CYC(6)  break;
    case 0xDF:   INV ABSX DCM       CYC(7)  break;
    case 0xE0:       IMM CPX       CYC(2)  break;
    case 0xE1:       INDX SBC_NMOS CYC(6)  break;
    case 0xE2:   INV IMM NOP       CYC(2)  break;
    case 0xE3:   INV INDX INS       CYC(8)  break;
    case 0xE4:       ZPG CPX       CYC(3)  break;
    case 0xE5:       ZPG SBC_NMOS  CYC(3)  break;
    case 0xE6:       ZPG INC_NMOS  CYC(5)  break;
    case 0xE7:   INV ZPG INS       CYC(5)  break;
    case 0xE8:       INX       CYC(2)  break;
    case 0xE9:       IMM SBC_NMOS  CYC(2)  break;
    case 0xEA:       NOP       CYC(2)  break;
    case 0xEB:   INV IMM SBC_NMOS  CYC(2)  break;
    case 0xEC:       ABS CPX       CYC(4)  break;
    case 0xED:       ABS SBC_NMOS  CYC(4)  break;
    case 0xEE:       ABS INC_NMOS  CYC(6)  break;
    case 0xEF:   INV ABS INS       CYC(6)  break;
    case 0xF0:       REL BEQ       CYC(2)  break;
    case 0xF1:       INDY SBC_NMOS CYC(5)  break;
    case 0xF2:   INV HLT       CYC(2)  break;
    case 0xF3:   INV INDY INS       CYC(8)  break;
    case 0xF4:   INV ZPGX NOP       CYC(4)  break;
    case 0xF5:       ZPGX SBC_NMOS CYC(4)  break;
    case 0xF6:       ZPGX INC_NMOS CYC(6)  break;
    case 0xF7:   INV ZPGX INS       CYC(6)  break;
    case 0xF8:       SED       CYC(2)  break;
    case 0xF9:       ABSY SBC_NMOS CYC(4)  break;
    case 0xFA:   INV NOP       CYC(2)  break;
    case 0xFB:   INV ABSY INS       CYC(7)  break;
    case 0xFC:   INV ABSX NOP       CYC(4)  break;
    case 0xFD:       ABSX SBC_NMOS CYC(4)  break;
    case 0xFE:       ABSX INC_NMOS CYC(6)  break;
    case 0xFF:   INV ABSX INS       CYC(7)  break;
    }

    CheckInterruptSources(uExecutedCycles);
    NMI(uExecutedCycles, uExtraCycles, flagc, flagn, flagv, flagz);
    IRQ(uExecutedCycles, uExtraCycles, flagc, flagn, flagv, flagz);

    if (bBreakOnInvalid)
      break;

  } while (uExecutedCycles < uTotalCycles);

  EF_TO_AF
  return uExecutedCycles;
}

//===========================================================================

static DWORD InternalCpuExecute (DWORD uTotalCycles)
{

#ifdef UPDATE_ALL_PER_CYCLE
    MB_Update();
#endif
  if (IS_APPLE2 || (g_Apple2Type == A2TYPE_APPLE2E))
    return Cpu6502(uTotalCycles);  // Apple ][, ][+, //e
  else
    return Cpu65C02(uTotalCycles);  // Enhanced Apple //e
}

//
// ----- ALL GLOBALLY ACCESSIBLE FUNCTIONS ARE BELOW THIS LINE -----
//

//===========================================================================

void CpuDestroy ()
{
  if (g_bCritSectionValid)
  {
//      DeleteCriticalSection(&g_CriticalSection);
    g_bCritSectionValid = false;
  }
}

//===========================================================================
// Pre:
//  Call this when an IO-reg is access & accurate cycle info is needed
// Post:
//  g_nCyclesExecuted
//  g_nCumulativeCycles
//
void CpuCalcCycles(ULONG nExecutedCycles)
{
  // Calc # of cycles executed since this func was last called
  ULONG nCycles = nExecutedCycles - g_nCyclesExecuted;
#ifdef UPDATE_ALL_PER_CYCLE
  _ASSERT( (LONG)nCycles >= 0 );
#endif
  g_nCyclesExecuted += nCycles;
  g_nCumulativeCycles += nCycles;
}

//===========================================================================

// Old method with g_uInternalExecutedCycles runs faster!
//        Old     vs    New
// - 68.0,69.0MHz vs  66.7, 67.2MHz  (with check for VBL IRQ every opcode)
// - 89.6,88.9MHz vs  87.2, 87.9MHz  (without check for VBL IRQ)
// -                  75.9, 78.5MHz  (with check for VBL IRQ every 128 cycles)
// -                 137.9,135.6MHz  (with check for VBL IRQ & MB_Update every 128 cycles)

#ifdef UPDATE_ALL_PER_CYCLE   // TODO: Measure perf increase by using this new method
ULONG CpuGetCyclesThisFrame(ULONG)  // Old func using g_uInternalExecutedCycles
{
  CpuCalcCycles(g_uInternalExecutedCycles);
  return g_dwCyclesThisFrame + g_nCyclesExecuted;
}
#else
ULONG CpuGetCyclesThisFrame(ULONG nExecutedCycles)
{
  CpuCalcCycles(nExecutedCycles);
  return g_dwCyclesThisFrame + g_nCyclesExecuted;
}
#endif

//===========================================================================

DWORD CpuExecute (DWORD uCycles)
{
  DWORD uExecutedCycles =  0;

  g_nCyclesSubmitted = uCycles;
  g_nCyclesExecuted =  0;

  //

  MB_StartOfCpuExecute();

  if (uCycles  == 0)  // Do single step
    uExecutedCycles  = InternalCpuExecute(0);
  else        // Do multi-opcode emulation
    uExecutedCycles  = InternalCpuExecute(uCycles);

#ifndef UPDATE_ALL_PER_CYCLE
  MB_UpdateCycles(uExecutedCycles);  // Update 6522s (NB. Do this before updating g_nCumulativeCycles below)
#endif
  //

  UINT nRemainingCycles = uExecutedCycles - g_nCyclesExecuted;
  g_nCumulativeCycles  += nRemainingCycles;

  return uExecutedCycles;
}

//===========================================================================

void CpuInitialize ()
{
  CpuDestroy();
  regs.a = regs.x = regs.y = regs.ps = 0xFF;
  regs.sp = 0x01FF;
  CpuReset();  // Init's ps & pc. Updates sp

//  InitializeCriticalSection(&g_CriticalSection);
//  g_CriticalSection = PTHREAD_MUTEX_INITIALIZER;
  g_bCritSectionValid = true;
  CpuIrqReset();
  CpuNmiReset();
}

//===========================================================================

void CpuSetupBenchmark ()
{
  regs.a  = 0;
  regs.x  = 0;
  regs.y  = 0;
  regs.pc = 0x300;
  regs.sp = 0x1FF;

  // CREATE CODE SEGMENTS CONSISTING OF GROUPS OF COMMONLY-USED OPCODES
  {
    int addr   = 0x300;
    int opcode = 0;
    do
    {
      *(mem+addr++) = benchopcode[opcode];
      *(mem+addr++) = benchopcode[opcode];

      if (opcode >= SHORTOPCODES)
        *(mem+addr++) = 0;

      if ((++opcode >= BENCHOPCODES) || ((addr & 0x0F) >= 0x0B))
      {
        *(mem+addr++) = 0x4C;
        *(mem+addr++) = (opcode >= BENCHOPCODES) ? 0x00 : ((addr >> 4)+1) << 4;
        *(mem+addr++) = 0x03;
        while (addr & 0x0F)
          ++addr;
      }
    } while (opcode < BENCHOPCODES);
  }
}

//===========================================================================

void CpuIrqReset()
{
  _ASSERT(g_bCritSectionValid);
  if (g_bCritSectionValid) pthread_mutex_lock(&g_CriticalSection);
  g_bmIRQ = 0;
  if (g_bCritSectionValid) pthread_mutex_unlock(&g_CriticalSection);
}

void CpuIrqAssert(eIRQSRC Device)
{
  _ASSERT(g_bCritSectionValid);
  if (g_bCritSectionValid) pthread_mutex_lock(&g_CriticalSection);
  g_bmIRQ |= 1<<Device;
  if (g_bCritSectionValid) pthread_mutex_unlock(&g_CriticalSection);
}

void CpuIrqDeassert(eIRQSRC Device)
{
  _ASSERT(g_bCritSectionValid);
  if (g_bCritSectionValid) pthread_mutex_lock(&g_CriticalSection);
  g_bmIRQ &= ~(1<<Device);
  if (g_bCritSectionValid) pthread_mutex_unlock(&g_CriticalSection);
}

//===========================================================================

void CpuNmiReset()
{
  _ASSERT(g_bCritSectionValid);
  if (g_bCritSectionValid) pthread_mutex_lock(&g_CriticalSection);
  g_bmNMI = 0;
  g_bNmiFlank = FALSE;
  if (g_bCritSectionValid) pthread_mutex_unlock(&g_CriticalSection);
}

void CpuNmiAssert(eIRQSRC Device)
{
  _ASSERT(g_bCritSectionValid);
  if (g_bCritSectionValid) pthread_mutex_lock(&g_CriticalSection);
  if (g_bmNMI == 0) // NMI line is just becoming active
      g_bNmiFlank = TRUE;
  g_bmNMI |= 1<<Device;
  if (g_bCritSectionValid) pthread_mutex_unlock(&g_CriticalSection);
}

void CpuNmiDeassert(eIRQSRC Device)
{
  _ASSERT(g_bCritSectionValid);
  if (g_bCritSectionValid) pthread_mutex_lock(&g_CriticalSection);
  g_bmNMI &= ~(1<<Device);
  if (g_bCritSectionValid) pthread_mutex_unlock(&g_CriticalSection);
}

//===========================================================================

void CpuReset()
{
  // 7 cycles
  regs.ps = (regs.ps | AF_INTERRUPT) & ~AF_DECIMAL;
  regs.pc = * (WORD*) (mem+0xFFFC);
  regs.sp = 0x0100 | ((regs.sp - 3) & 0xFF);

  regs.bJammed = 0;
}

//===========================================================================

DWORD CpuGetSnapshot(SS_CPU6502* pSS)
{
  pSS->A = regs.a;
  pSS->X = regs.x;
  pSS->Y = regs.y;
  pSS->P = regs.ps | AF_RESERVED | AF_BREAK;
  pSS->S = (BYTE) (regs.sp & 0xff);
  pSS->PC = regs.pc;
  pSS->g_nCumulativeCycles = g_nCumulativeCycles;

  return 0;
}

DWORD CpuSetSnapshot(SS_CPU6502* pSS)
{
  regs.a = pSS->A;
  regs.x = pSS->X;
  regs.y = pSS->Y;
  regs.ps = pSS->P | AF_RESERVED | AF_BREAK;
  regs.sp = (USHORT)pSS->S | 0x100;
  regs.pc = pSS->PC;
  CpuIrqReset();
  CpuNmiReset();
  g_nCumulativeCycles = pSS->g_nCumulativeCycles;

  return 0;
}