-
Notifications
You must be signed in to change notification settings - Fork 9
/
Copy pathRRDX2.ASM
executable file
·668 lines (562 loc) · 18.8 KB
/
RRDX2.ASM
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
OPT NOL
LIB RRF
OPT LIS
STTL DIAGONAL EXPLOSIONS
*
* EXPLODING OBJECT DATA STRUCTURE
*
ORG DXTAB PLACE FOR DATA
EX EQU *
NEXTZ RMB 2 LIST POINTER
PICPTZ RMB 2 POINTER TO DATA
XCENTZ RMB 1 SCREEN X CENTER (LEFT X OF CENTER LINE)
YCENTZ RMB 1 SCREEN Y CENTER
YOFZ RMB 1 OFFSET IN Y TO OBJECT CENTER (PIXELS) (0-HEIGHT)
XSIZEZ RMB 1 X SIZE USED LAST (THIS) FRAME
YSIZEZ RMB 2 CURRENT Y POINT SPACING
FRAMEZ RMB 1 FRAMES TO RUN IN EFFECT
ULZ RMB 2 UPPER LEFT
WHZ RMB 2 WIDTH,HEIGHT
DMAWHZ RMB 2 DMA HEIGHT WIDTH
YHITEZ RMB 1
SLOPEZ RMB 1 SLOPE OF DIAGONAL LINE WE ARE EXPLODING (SIGN BIT)
DATAZ RMB 16*2 LIST OF ROW DATA POINTERS (FOR SPEED MAN)
ESIZEZ EQU *
NEXT EQU NEXTZ-EX
PICPTR EQU PICPTZ-EX
XCENT EQU XCENTZ-EX
YCENT EQU YCENTZ-EX
YOF EQU YOFZ-EX
XSIZER EQU XSIZEZ-EX
YSIZER EQU YSIZEZ-EX
FRAMES EQU FRAMEZ-EX
UL EQU ULZ-EX
WH EQU WHZ-EX
DMAWH EQU DMAWHZ-EX
YHITE EQU YHITEZ-EX
SLOPE EQU SLOPEZ-EX
DATA EQU DATAZ-EX
EXSIZE EQU ESIZEZ-EX
RMB ((10-1)*EXSIZE) NUMBER OF BLOCKS
EXEND EQU *
ORG DXRAM (BASE PAGE)
YYCNT RMB 1 WHEN CHOPPING UP X, SAVE TO UPDATE ULY
YOFF RMB 1 ACTUAL PIXEL OFFSET TO CENTER (USED)
XSIZE RMB 1 DISTANCE BETWEEN X POINTS THIS FRAME
YSIZE RMB 1 DISTANCE BETWEEN Y POINTS THIS FRAME
EXPTR RMB 2
APPTR RMB 2 APPEAR POINTER
EXFREE RMB 2
HITE RMB 1
TEMP1 RMB 2
TEMP2 RMB 1
*
*VECTORS
*
ORG RDXORG
JMP EXINV
JMP EXSTZ
JMP APSTZ
JMP DXUPDV
*
*INIT DATA STRUCT
*
EXINV PSHS X,Y
LDX #EX FIRST
STX EXFREE
EXIN0 LEAY EXSIZE,X FIND NEXT
STY ,X STORE
CMPY #EXEND DONE??
BHS EXIN1
LEAX ,Y MAKE US NEXT
BRA EXIN0
EXIN1 LDY #0
STY ,X
STY EXPTR
STY APPTR
PULS X,Y,PC
GETBLK PSHS Y
LDU EXFREE
BEQ NOBLK NONE
LDY ,U GET NEXT
STY EXFREE
LDY EXPTR GET LIST
STY ,U APPEND US
STU EXPTR
CLC
PULS Y,PC RETURN IN U
NOBLK SEC
PULS Y,PC
GETAP PSHS Y
LDU EXFREE
BEQ NOBLK
LDY ,U
STY EXFREE
LDY APPTR
STY ,U
STU APPTR
CLC
PULS Y,PC
*
*START AN APPEAR
*X=OBJ,A=SLOPE
APSTZ PSHS X,Y,D,U
JSR GETAP GET AN APPEAR BLOCK
BCS APBY NONE
STA SLOPE,U SAVE SLOPE
LDD OBJX,X
LDX OPICT,X
STD UL,U START AS UPPER LEFT
STA XCENT,U SAVE X CENTER
LDB CENTMP+1
STB YCENT,U
SUBB UL+1,U SUBTRACT Y UPPER LEFT
BCS NWCEAP NO GOOD
CMPB 1,X COMPARE
BLO APNTOK
NWCEAP LDB ,X GET WIDTH
LSRB 1/2 Y
STB YOF,U SAVE OFFSET
ADDB UL+1,U ADD TOP
STB YCENT,U THIS IS
BRA CCOAP
APNTOK STB YOF,U
CCOAP LDD ,X FETCH H,W
STD WH,U SAVE
LDB #1 HEIGHT IS 1 FOR DMA
STB YHITE,U SMALL HEIGHT FOR FIRST (CRAZY) ERASE
EORA #$4
EORB #$4
STD DMAWH,U FORMED
LDX 2,X GET DATA POINTER
STX PICPTR,U SAVE OBJECT DESC
LDD #$1000 START LARGE FOR APPEAR
STD YSIZER,U
CLR XSIZER,U ERASE NORMAL OBJECT FIRST FRAME
BSR DATALD LOAD THE ROW DATA PTRS
APBY PULS X,D,U,PC,Y AND RETURN TO CALLER
DATALD LDX PICPTR,U GET POINTER TO DATA
LDB WH,U WIDTH IN B
LDA WH+1,U HEIGHT IN A
LEAU DATA,U POINT AT THE DATA
DATLD1 STX ,U++ STORE POINTER TO CURRENT ROW
ABX ADDING WIDTH FORMS POINTER TO NEXT ROW
DECA 1 LESS ROW (OFF HEIGHT)
BNE DATLD1 DONE?
RTS YEP
*
*START AN EXPLOSION
*X=OBJ,A=SLOPE
EXSTZ PSHS X,U,D,Y
JSR GETBLK GET A BLOCK TO USE
BCS EXBYE DONE...NO BLOCKS
STA SLOPE,U
LDD OBJX,X
LDX OPICT,X
STD UL,U STORE UPPER LEFT (FIRST FRAME)
STA XCENT,U SAVE LEFT X
LDB CENTMP+1
STB YCENT,U
SUBB UL+1,U SUBTRACT Y UPPER LEFT
BCS NWCENT NO GOOD
CMPB 1,X COMPARE
BLO CENTOK
NWCENT LDB ,X GET WIDTH
LSRB 1/2 Y
STB YOF,U SAVE OFFSET
ADDB UL+1,U ADD TOP
STB YCENT,U THIS IS
BRA CCONT
CENTOK STB YOF,U
CCONT LDD ,X FETCH H,W
STD WH,U SAVE
STB YHITE,U HITE FOR FIRST ERASE
LDB #1 HEIGHT IS 1 FOR DMA
EORA #$4
EORB #$4
STD DMAWH,U FORMED
LDX 2,X GET DATA POINTER
STX PICPTR,U SAVE OBJECT DESC
LDD #$100 1 UNIT IS MIN
STD YSIZER,U
CLR XSIZER,U
LDA #$10 NUMBER OF BYTES TO ERASE, NUMBER OF FRAMES LEFT
STA FRAMES,U
BSR DATALD LOAD THE ROW POINTERS
EXBYE PULS X,D,U,PC,Y AND RETURN TO CALLER
* THIS CODE DMA'S THE DMASIZONTAL LINES
* A JUMP INTO HERE IS MADE BASED ON NUMBER OF
* DMASIZONTAL LINES IN OBJECT
BSLOOP LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
BSSIZE EQU *-BSLOOP
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
ADDD XSIZE KICK POINTER TO NEXT ONE
LDX ,Y++ GET THE ROW POINTER
STX DMAORG THIS IS ORIGIN
STD DMADES D IS DEST
STU DMACTL THIS IS THE CONTROL REGISTER
CLI
PULS Y,PC RESTORE Y, RETURN
ERLOOP STD DMADES DEST TO ERASE
STU DMACTL-1 BYTE TO DO IT
ADDD XSIZE ADD OFFSETS
ERSIZ EQU *-ERLOOP
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
STD DMADES
STU DMACTL-1
ADDD XSIZE
CLI
RTS
ERASE LDB YHITE,Y ACTUALLY PLOTTED
SUBB #16 MAX OF 16
NEGB
ASLB
ASLB
ASLB
LDX #ERLOOP
ABX
LDD XSIZER,Y
STD XSIZE
LDA RWCTMP GET RWBYTE
LDB #$12 ERASE
TFR D,U
LDD #0
SEI
STD DMACON CONSTANT, AND HIGH HALF OF DMAORG
LDD DMAWH,Y
STD DMASIZ
LDD UL,Y DMADESINATION STARTS WITH UPPER LEFT
JMP ,X
KILEXP LDU #EXPTR LETS WALK LIST TO FIND HIM
KILEX2 CMPY ,U ARE WE SET
BEQ KILEX1 YEP
LDU ,U KEEP WALKING
BNE KILEX2 STILL STUFF THERE
SEI
BRA * ERROR TRAP
KILEX1 LDD ,Y GET GUY WE POINT AT
STD ,U POINT AROUND US
LDD EXFREE
STD ,Y APPEND FREE LIST
STY EXFREE
LEAY ,U RETURN GUY BEFORE US TO WALK FROM
RTS DONE!
*
*WRITE YOUR APPEAR!!!
*Y=EXPLOSION
AWRITE LDD YSIZER,Y
SUBD #$100
CMPA YSIZER,Y ANY SIZE CHANGE?
BNE AWRIT0 YES
STB YSIZER+1,Y NO DICE
RTS
AWRIT0 JSR ERASE
LDA STATUS
BNE AWRIT1
LDD PX SCROLL THE COCK SUCKER
STA XCENT,Y
ADDB YOF,Y
STB YCENT,Y
AWRIT1 LDA WH+1,Y GET HEIGHT
STA HITE PRELIMINARY ATTEMPT AT HEIGHT
LDD YSIZER,Y GET CURRENT SIZE
SUBD #$0100 TAKE AWAY SOME SIZE
CMPA #1
BHI APGO DONE!
LDU #APPTR FIND HE WHO POINTS AT HIM....NOW KILL IT
BRA KILEX2 NOW ITS JUST LIKE AN EXPLODE KILL
WRITE DEC FRAMES,Y ONE LESS FRAME
BEQ KILEXP DONE
LDA WH+1,Y GET HEIGHT
STA HITE
LDD YSIZER,Y
ADDD #$100
APGO STA YSIZE
STD YSIZER,Y
LSRA 1/2 FOR X SIZE
STA TEMP2 ALSO SAVE TO ADD 1/2 SIZE UNIT FOR CENTER LINE
LDB SLOPE,Y CHECK SLOPE
BPL APGG1 POSITIVE
NEGA NEGATIVE
APGG1 STA XSIZER,Y AND SAVE
STA XSIZE SCRATCH SOME SPEED
LDB YOF,Y CHECK FOR ZERO OFFSET
BNE APGO1
STB TEMP2 IF DOWN FROM TOP....FIX TOP ONE (OBSCURE BUG)
APGO1 LDA YSIZE
LDB YOF,Y GET OFFSET
STB YOFF SAVE FOR X CALCULATION
MUL DISTANCE UP FROM CENTER
STD TEMP1 SAVE
LDB YCENT,Y GET CENTER
CLRA
SUBD TEMP1 LETS BE GENERAL PURPOSE
ADDB TEMP2 ADD 1/2 SIZE
ADCA #0 AND PROPAGATE
BNE CHK2 NO GOOD..TIME TO SCREW AROUND
*
* DON'T WORRY EUGENE...I GOT THIS FIX THIS TIME
*
CMPB #YMIN
BHI CHK3 IN RANGE
CHK2 DEC HITE 1 LESS
DEC YOFF
ADDB YSIZE BRING BACK FROM NEGATIVE NOWHERE
ADCA #0
BNE CHK2 AND LOOP A WHILE
CMPB #YMIN POSITIVE-VILLE...BIG ENOUGH
BLS CHK2 NOPE
CHK3 STB UL+1,Y STORE IN PLACE
LDA YOFF ACTUAL Y OFFSET USED
LDB XSIZE WHICH SLOPE??
BMI XNEG BUMMER
MUL FIND DEFLECTION
STD TEMP1 WHERE HAVE I SEED CODE LIKE THIS
LDB XCENT,Y GET X "CENTER"
CLRA X CENTER HAS BEEN COMPUTED
SUBD TEMP1 FIND WHERE LEFTMOST X OCCURS
TSTA NEGATIVE??
BNE CKK2A YEP...SHIFT IT IN
CMPB #XMIN IN RANGE??
BHI CKK3AA RIGHT ON
CKK2A CLR YYCNT COUNT TO UDPATE 1 STARTING POINT
CKK2B DEC HITE CHOP SOME MORE AWAY
INC YYCNT INCICATE 1 MORE
ADDB XSIZE ADD THE X UNITS
ADCA #0
BNE CKK2B AND ITERATE
CMPB #XMIN
BLS CKK2B THANK YOU SIR MAY I HAVE ANOTHER
CKK3C STB UL,Y THIS IS THE UPPER LEFT X
LDB YYCNT GET THE YER
LDA YSIZE GET Y SIZE
MUL NUMBER OF Y UNITS FROM X CLIP
ADDB UL+1,Y
STB UL+1,Y
BRA CKK3B
XNEG NEGB MAKE SIZE POSITIVE (NEG STATE BY CONTROL HERE)
MUL NUMBER OF BYTES POS DISPLACEMENT
ADDB WH,Y ADD IN THE WIDTH, (GUAR NO CARRY IF SIZE<32I
ADDB XCENT,Y ADD CENTER TO FIND LAST PIXEL PLOTTED
ADCA #0 ALL RIGHT!
BNE XN2 NO GOOD...BIG CARRY
CMPB #XMAX IN RANGE??
BLS CKK3A SAME IS OK SINCE THIS IS 1 BEYOND OB
XN2 CLR YYCNT WE NEED TO KNOW HOW MANY CLIPPED
XN22 DEC HITE 1 MORE Y UNIT
INC YYCNT
ADDB XSIZE ADD THE SIZE (REMEMBER, ITS NEGATIVE)
ADCA #$FF ADD EXTENDED SIGN
BNE XN22 STILL TOO LARGE
CMPB #XMAX DID WE MAKE IT??
BHI XN22 NOPE
SUBB WH,Y REMOVE THE WIDTH TO GET BACK TO LEFT
BRA CKK3C ADJUST Y FOR THE DAMAGES
* (CKK3C IS UP, EUGENE)
CKK3A SUBB WH,Y GET BACK TO LEFT OF OB
CKK3AA STB UL,Y SAVE GOOD X
CKK3B LEAX DATA,Y POINT AT FIRST ITEM
LDB WH+1,Y GET HEIGHT
SUBB HITE FIND NUMBER WE WILL SKIP
ASLB POINTERS ARE 2 BYTES
ABX WE NOW POINT AT FIRST ONE WE WILL USE
*
* TIME FOR THE BUTT CLIP
*
LDA HITE GET HEIGHT
DECA
LDB YSIZE FIND FILL DEFLECTION
MUL
ADDB UL+1,Y ADD FIRST POINT
ADCA #0 FIND FULL DEFLECTION
BEQ CHK4 AOK
CHK5 DEC HITE 1 LESS
BEQ KLJMP EXIT IMMEDIATELY ON TOTAL CLIP
SUBB YSIZE 1 LESS DOWNWARD
SBCA #0
BNE CHK5
CHK4 CMPB #YMAX
BHS CHK5
LDA HITE GET HITE BACK
DECA FIRSTIES DON'T COUNT
LDB XSIZE GET X SIZE
BMI XNT NEGATIVE SLOPE
MUL DEFLECTION OF LAST GUY
ADDB WH,Y ADD WIDTH
ADDB UL,Y ADD STARTING X
ADCA #0 PROP IT
BEQ NCK4 NOT HUGE
NCK5 DEC HITE TAKE 1 AWAY
BEQ KLJMP TOTAL CLIP...BYE
SUBB XSIZE TRY AND BRING DOWN TO SIZE
SBCA #0
BNE NCK5
NCK4 CMPB #XMAX
BHI NCK5 EQUAL IS OK
BRA NCK6
XNT NEGB MAKE
MUL
STD TEMP1 SAVE OFFSET
LDB UL,Y GET UPPER LEFT
CLRA
SUBD TEMP1 REMOVE OFFSET
TSTA
BEQ NNCK4 NOT WAY TOO SMALL
NNCK5 DEC HITE 1 LESS
BEQ KLJMP
SUBB XSIZE ADDING NEG MOVES US POSITVE
SBCA #$FF SUB SIGN EXT
BNE NNCK5 KEEP GOING
NNCK4 CMPB #XMIN
BLS NNCK5 KEEP GOING
* FIND "LOOP" ENTRY
NCK6 LDA HITE GET HEIGHT
BNE NOKILE
KLJMP JMP KILEXP NO HEIGHT
NOKILE STA YHITE,Y SAVE FOR ERASE
SUBA #16 16 = 0 OFFSET, 0 = 16 OFFSET
NEGA
LDB #BSSIZE SIZE OF ITERATION
MUL
ADDD #BSLOOP BEGINNING
PSHS D,Y SETUP STACK AS FOLLOWS:
* PTR -> D = JUMP ADDRESS
* Y = PUSHED TO SAVE FOR RTS
* <RETURN ADDRESS>
* PULS Y,PC AT END OF LOOP CAUSES PROPER RETURN
LDU #$0A0A CONTROL REGISTER
LDD DMAWH,Y GET WH
SEI NO INTS BABY
STD DMASIZ
LDD UL,Y GET DMADESINATION IN D
LEAY ,X MAKE Y POINT AT PROPER DATA GUY
RTS RETURN, MY ASS!
*
*UPDATE YOUR DIAGONALS
*
DXUPDV LDY EXPTR
BEQ APUPD
DXUPDL JSR ERASE
JSR WRITE
LDY ,Y
BNE DXUPDL
APUPD LDY APPTR
BEQ APUPDX
APUPDL JSR AWRITE
LDY ,Y
BNE APUPDL
APUPDX RTS
END