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
|
//void fXXX(ADDRESSING addr, int val)
// Load and Store Instructions
void fLDA(Addressing addr, int val){
acc = fAddressing(addr, val);
}
void fLDX(Addressing addr, int val){
X = fAddressing(addr, val);
}
void fLDY(Addressing addr, int val){
Y = fAddressing(addr, val);
}
void fSTA(Addressing addr, int val){
Memory[(fAddressing(addr, val))] = acc;
}
void fSTX(Addressing addr, int val){
Memory[(fAddressing(addr, val))] = X;
}
void fSTY(Addressing addr, int val){
Memory[(fAddressing(addr, val))] = Y;
}
// Arithmetic Instructions
void fADC(Addressing addr, int val){
int buffer = acc + fAddressing(addr, val);
setFlagV(buffer, acc);
if (buffer > 255){
setFlag(flag_C, 1);
}else{
setFlag(flag_C, 0);
}
acc += fAddressing(addr, val);
setFlagN(acc);
setFlagZ(acc);
}
void fSBC(Addressing addr, int val){
int buffer = acc - fAddressing(addr, val);
setFlagV(buffer, acc);
if (buffer < 0){
setFlag(flag_C, 1);
}else{
setFlag(flag_C, 0);
}
acc -= fAddressing(addr, val);
setFlagN(acc);
setFlagZ(acc);
}
//Increment and Decrement Instructions
// Logical Instructions
void fAND(Addressing addr, int val){
acc = acc & fAddressing(addr, val);
setFlagN();
setFlagZ(acc);
}
void fORA(Addressing addr, int val){
acc = acc | fAddressing(addr, val);
setFlagN();
setFlagZ(acc);
}
void fEOR(Addressing addr, int val){
acc = acc ^ fAddressing(addr, val);
setFlagN(acc);
setFlagZ(acc);
}
// Jump, Branch, Compare, and Test Bits
// Shift and Rotate Instructions
void fASL(Addressing addr, int val){
setFlag(flag_C, (val & 0x80));
acc = (val << 1);
setFlagN(acc);
setFlagZ(acc);
}
// Transfer Instructions
// Stack Instructions
// Subroutine Instructions
// Set/Reset Insutrctions
void fCLC(){
setFlag(flag_C, 0);
}
void fCLD(){
setFlag(flag_D, 0);
}
void fCLI(){
setFlag(flag_I, 0);
}
void fCLV(){
setFlag(flag_V, 0);
}
void fSEC(){
setFlag(flag_C, 1);
}
void fSED(){
setFlag(flag_D, 1);
}
void fSEI(){
setFlag(flag_I, 1);
}
// NOP/BRK Instructions
/* Disabled for the purpose of testing functions.
this will become relevant towards the end of project.
// Instruction Meta
// Alternative would be to make all functions pointer functions, and then look them up
//according to the code in such a way. It may be more readable that way.
void runInstruction(int code, int val){
switch(code){
// 0x0.
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
case 0x0
// 0x1.
case 0x10
case 0x11
case 0x12
case 0x13
case 0x14
case 0x15
case 0x16
case 0x17
case 0x18: fCLC();
case 0x1
case 0x1
case 0x1
case 0x1
case 0x1
case 0x1
case 0x1
// 0x2.
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
case 0x2
// 0x3.
case 0x30
case 0x31
case 0x32
case 0x33
case 0x34
case 0x35
case 0x36
case 0x37
case 0x38: fSEC();
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0x4.
case 0x40:
case 0x41:
case 0x42:
case 0x43:
case 0x44:
case 0x45:
case 0x46:
case 0x47:
case 0x48:
case 0x49:
case 0x4A:
case 0x4B:
case 0x4C:
case 0x4D:
case 0x4E:
case 0x4F:
// 0x5.
case 0x50:
case 0x51:
case 0x52:
case 0x53:
case 0x54:
case 0x55:
case 0x56:
case 0x57:
case 0x58: fCLI();
case 0x59:
case 0x5A:
case 0x5B:
case 0x5C:
case 0x5D:
case 0x5E:
case 0x5F:
// 0x6.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0x7.
case 0x70
case 0x71
case 0x72
case 0x73
case 0x74
case 0x75
case 0x76
case 0x77
case 0x78: fSEI();
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0x8.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0x9.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0xA.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0xB.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0xB8: fCLV();
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0xC.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0xD.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0xD8: fCLD();
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0xE.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
// 0xF.
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0xF8: fSED();
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
case 0x
default: //Error
}
}
*/
|
